21019557120 has 432 divisors, whose sum is σ = 72331600320. Its totient is φ = 5199888384.

The previous prime is 21019557109. The next prime is 21019557133. The reversal of 21019557120 is 2175591012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 81788032 + ... + 81788288.

It is an arithmetic number, because the mean of its divisors is an integer number (167434260).

Almost surely, 2^21019557120 is an apocalyptic number.

21019557120 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 21019557120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36165800160).

21019557120 is an abundant number, since it is smaller than the sum of its proper divisors (51312043200).

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

21019557120 is a wasteful number, since it uses less digits than its factorization.

21019557120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 33.

The spelling of 21019557120 in words is "twenty-one billion, nineteen million, five hundred fifty-seven thousand, one hundred twenty".