21853853688 has 16 divisors (see below), whose sum is σ = 54634634280. Its totient is φ = 7284617888.

The previous prime is 21853853677. The next prime is 21853853699. The reversal of 21853853688 is 88635835812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21853853677) and next prime (21853853699).

It is a super-2 number, since 2×21853853688² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455288595 + ... + 455288642.

Almost surely, 2^21853853688 is an apocalyptic number.

It is an amenable number.

21853853688 is an abundant number, since it is smaller than the sum of its proper divisors (32780780592).

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

21853853688 is a wasteful number, since it uses less digits than its factorization.

21853853688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910577246 (or 910577242 counting only the distinct ones).

The product of its digits is 11059200, while the sum is 57.

The spelling of 21853853688 in words is "twenty-one billion, eight hundred fifty-three million, eight hundred fifty-three thousand, six hundred eighty-eight".