21600851356 has 12 divisors (see below), whose sum is σ = 43201702768. Its totient is φ = 9257507712.

The previous prime is 21600851351. The next prime is 21600851357. The reversal of 21600851356 is 65315800612.

21600851356 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21600851351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385729461 + ... + 385729516.

Almost surely, 2^21600851356 is an apocalyptic number.

It is an amenable number.

21600851356 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21600851356 is a wasteful number, since it uses less digits than its factorization.

21600851356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771458988 (or 771458986 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 37.

The spelling of 21600851356 in words is "twenty-one billion, six hundred million, eight hundred fifty-one thousand, three hundred fifty-six".