20891534220 has 72 divisors (see below), whose sum is σ = 65083737264. Its totient is φ = 5420504448.

The previous prime is 20891534207. The next prime is 20891534233. The reversal of 20891534220 is 2243519802.

It is a happy number.

20891534220 is a `hidden beast` number, since 2 + 0 + 89 + 153 + 422 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20891534207) and next prime (20891534233).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1561774 + ... + 1575093.

Almost surely, 2^20891534220 is an apocalyptic number.

20891534220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20891534220 is an abundant number, since it is smaller than the sum of its proper divisors (44192203044).

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

20891534220 is a wasteful number, since it uses less digits than its factorization.

20891534220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3136919 (or 3136914 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 20891534220 in words is "twenty billion, eight hundred ninety-one million, five hundred thirty-four thousand, two hundred twenty".