21056057000 has 96 divisors (see below), whose sum is σ = 54157881960. Its totient is φ = 7656704000.

The previous prime is 21056056981. The next prime is 21056057003. The reversal of 21056057000 is 75065012.

It can be written as a sum of positive squares in 4 ways, for example, as 12732414244 + 8323642756 = 112838^2 + 91234^2 .

It is not an unprimeable number, because it can be changed into a prime (21056057003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33992 + ... + 208008.

Almost surely, 2^21056057000 is an apocalyptic number.

21056057000 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 21056057000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27078940980).

21056057000 is an abundant number, since it is smaller than the sum of its proper divisors (33101824960).

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

21056057000 is a wasteful number, since it uses less digits than its factorization.

21056057000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174060 (or 174035 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 26.

The spelling of 21056057000 in words is "twenty-one billion, fifty-six million, fifty-seven thousand".