21125131245040 has 80 divisors (see below), whose sum is σ = 52091924385600. Its totient is φ = 7939713167360.

The previous prime is 21125131244969. The next prime is 21125131245041. The reversal of 21125131245040 is 4054213152112.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 21125131244993 and 21125131245011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21125131245041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12151291 + ... + 13780570.

It is an arithmetic number, because the mean of its divisors is an integer number (651149054820).

Almost surely, 2^{21125131245040} is an apocalyptic number.

21125131245040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21125131245040 is an abundant number, since it is smaller than the sum of its proper divisors (30966793140560).

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

21125131245040 is a wasteful number, since it uses less digits than its factorization.

21125131245040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25932490 (or 25932484 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 21125131245040 its reverse (4054213152112), we get a palindrome (25179344397152).

The spelling of 21125131245040 in words is "twenty-one trillion, one hundred twenty-five billion, one hundred thirty-one million, two hundred forty-five thousand, forty".