20001072156 has 96 divisors (see below), whose sum is σ = 52366583808. Its totient is φ = 5899841280.

The previous prime is 20001072109. The next prime is 20001072163. The reversal of 20001072156 is 65127010002.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 498126 + ... + 536778.

It is an arithmetic number, because the mean of its divisors is an integer number (545485248).

Almost surely, 2^20001072156 is an apocalyptic number.

20001072156 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20001072156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26183291904).

20001072156 is an abundant number, since it is smaller than the sum of its proper divisors (32365511652).

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

20001072156 is a wasteful number, since it uses less digits than its factorization.

20001072156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38811 (or 38809 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 24.

Adding to 20001072156 its reverse (65127010002), we get a palindrome (85128082158).

The spelling of 20001072156 in words is "twenty billion, one million, seventy-two thousand, one hundred fifty-six".