20351431520 has 96 divisors (see below), whose sum is σ = 55189512000. Its totient is φ = 6947076096.

The previous prime is 20351431519. The next prime is 20351431543. The reversal of 20351431520 is 2513415302.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20351431520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216806 + ... + 296154.

It is an arithmetic number, because the mean of its divisors is an integer number (574890750).

Almost surely, 2^20351431520 is an apocalyptic number.

20351431520 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 20351431520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27594756000).

20351431520 is an abundant number, since it is smaller than the sum of its proper divisors (34838080480).

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

20351431520 is a wasteful number, since it uses less digits than its factorization.

20351431520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79600 (or 79592 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 20351431520 its reverse (2513415302), we get a palindrome (22864846822).

The spelling of 20351431520 in words is "twenty billion, three hundred fifty-one million, four hundred thirty-one thousand, five hundred twenty".