20525721560 has 128 divisors (see below), whose sum is σ = 47841995520. Its totient is φ = 7921385472.

The previous prime is 20525721509. The next prime is 20525721563. The reversal of 20525721560 is 6512752502.

It is a self number, because there is not a number n which added to its sum of digits gives 20525721560.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20525721563) 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, 58146344 + ... + 58146696.

It is an arithmetic number, because the mean of its divisors is an integer number (373765590).

Almost surely, 2^20525721560 is an apocalyptic number.

20525721560 is a gapful number since it is divisible by the number (20) 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 20525721560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23920997760).

20525721560 is an abundant number, since it is smaller than the sum of its proper divisors (27316273960).

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

20525721560 is a wasteful number, since it uses less digits than its factorization.

20525721560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765 (or 761 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 35.

The spelling of 20525721560 in words is "twenty billion, five hundred twenty-five million, seven hundred twenty-one thousand, five hundred sixty".