20591232870 has 64 divisors (see below), whose sum is σ = 53449066944. Its totient is φ = 5046835200.

The previous prime is 20591232853. The next prime is 20591232887. The reversal of 20591232870 is 7823219502.

It is an interprime number because it is at equal distance from previous prime (20591232853) and next prime (20591232887).

It is a super-2 number, since 2×20591232870² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22431 + ... + 204170.

It is an arithmetic number, because the mean of its divisors is an integer number (835141671).

Almost surely, 2^20591232870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20591232870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26724533472).

20591232870 is an abundant number, since it is smaller than the sum of its proper divisors (32857834074).

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

20591232870 is a wasteful number, since it uses less digits than its factorization.

20591232870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226857.

The product of its (nonzero) digits is 60480, while the sum is 39.

The spelling of 20591232870 in words is "twenty billion, five hundred ninety-one million, two hundred thirty-two thousand, eight hundred seventy".