20506253240 has 128 divisors (see below), whose sum is σ = 52095191040. Its totient is φ = 7197120000.

The previous prime is 20506253219. The next prime is 20506253263. The reversal of 20506253240 is 4235260502.

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, 5740655 + ... + 5744225.

It is an arithmetic number, because the mean of its divisors is an integer number (406993680).

Almost surely, 2^20506253240 is an apocalyptic number.

20506253240 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 20506253240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26047595520).

20506253240 is an abundant number, since it is smaller than the sum of its proper divisors (31588937800).

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

20506253240 is a wasteful number, since it uses less digits than its factorization.

20506253240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4045 (or 4041 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 29.

The spelling of 20506253240 in words is "twenty billion, five hundred six million, two hundred fifty-three thousand, two hundred forty".