20749532856 has 32 divisors (see below), whose sum is σ = 55864127760. Its totient is φ = 6384471552.

The previous prime is 20749532849. The next prime is 20749532887. The reversal of 20749532856 is 65823594702.

It is a happy number.

It is a super-2 number, since 2×20749532856² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20749532799 and 20749532808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33252145 + ... + 33252768.

Almost surely, 2^20749532856 is an apocalyptic number.

20749532856 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20749532856 is an abundant number, since it is smaller than the sum of its proper divisors (35114594904).

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

20749532856 is a wasteful number, since it uses less digits than its factorization.

20749532856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66504935 (or 66504931 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 51.

The spelling of 20749532856 in words is "twenty billion, seven hundred forty-nine million, five hundred thirty-two thousand, eight hundred fifty-six".