20531751972 has 96 divisors (see below), whose sum is σ = 51998373504. Its totient is φ = 6280243200.

The previous prime is 20531751971. The next prime is 20531752061. The reversal of 20531751972 is 27915713502.

It is not an unprimeable number, because it can be changed into a prime (20531751971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5796522 + ... + 5800062.

It is an arithmetic number, because the mean of its divisors is an integer number (541649724).

Almost surely, 2^20531751972 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20531751972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25999186752).

20531751972 is an abundant number, since it is smaller than the sum of its proper divisors (31466621532).

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

20531751972 is a wasteful number, since it uses less digits than its factorization.

20531751972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4269 (or 4267 counting only the distinct ones).

The product of its (nonzero) digits is 132300, while the sum is 42.

The spelling of 20531751972 in words is "twenty billion, five hundred thirty-one million, seven hundred fifty-one thousand, nine hundred seventy-two".