21056160840 has 256 divisors, whose sum is σ = 74952864000. Its totient is φ = 4664832000.

The previous prime is 21056160821. The next prime is 21056160871. The reversal of 21056160840 is 4806165012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1727086 + ... + 1739234.

It is an arithmetic number, because the mean of its divisors is an integer number (292784625).

Almost surely, 2^21056160840 is an apocalyptic number.

21056160840 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 21056160840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37476432000).

21056160840 is an abundant number, since it is smaller than the sum of its proper divisors (53896703160).

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

21056160840 is a wasteful number, since it uses less digits than its factorization.

21056160840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12288 (or 12284 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The spelling of 21056160840 in words is "twenty-one billion, fifty-six million, one hundred sixty thousand, eight hundred forty".