20561325252 has 96 divisors (see below), whose sum is σ = 52069761408. Its totient is φ = 6277423104.

The previous prime is 20561325227. The next prime is 20561325259. The reversal of 20561325252 is 25252316502.

It is a super-2 number, since 2×20561325252² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20561325259) 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, 16950198 + ... + 16951410.

It is an arithmetic number, because the mean of its divisors is an integer number (542393348).

Almost surely, 2^20561325252 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 20561325252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26034880704).

20561325252 is an abundant number, since it is smaller than the sum of its proper divisors (31508436156).

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

20561325252 is a wasteful number, since it uses less digits than its factorization.

20561325252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989 (or 1987 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 33.

The spelling of 20561325252 in words is "twenty billion, five hundred sixty-one million, three hundred twenty-five thousand, two hundred fifty-two".