21157061700 has 36 divisors (see below), whose sum is σ = 61214432720. Its totient is φ = 5641883040.

The previous prime is 21157061693. The next prime is 21157061701. The reversal of 21157061700 is 716075112.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21157061701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35261470 + ... + 35262069.

Almost surely, 2^21157061700 is an apocalyptic number.

21157061700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21157061700 is an abundant number, since it is smaller than the sum of its proper divisors (40057371020).

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

21157061700 is a wasteful number, since it uses less digits than its factorization.

21157061700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70523556 (or 70523549 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 30.

The spelling of 21157061700 in words is "twenty-one billion, one hundred fifty-seven million, sixty-one thousand, seven hundred".