21057519125240 has 256 divisors, whose sum is σ = 52730129088000. Its totient is φ = 7517834311680.

The previous prime is 21057519125231. The next prime is 21057519125249. The reversal of 21057519125240 is 4252191575012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21057519125231) and next prime (21057519125249).

It is a super-2 number, since 2×21057519125240² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21057519125191 and 21057519125200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21057519125249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3000070451 + ... + 3000077469.

It is an arithmetic number, because the mean of its divisors is an integer number (205977066750).

Almost surely, 2^{21057519125240} is an apocalyptic number.

21057519125240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21057519125240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26365064544000).

21057519125240 is an abundant number, since it is smaller than the sum of its proper divisors (31672609962760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21057519125240 is a wasteful number, since it uses less digits than its factorization.

21057519125240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8030 (or 8026 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 44.

The spelling of 21057519125240 in words is "twenty-one trillion, fifty-seven billion, five hundred nineteen million, one hundred twenty-five thousand, two hundred forty".