20510251320 has 128 divisors (see below), whose sum is σ = 66335754240. Its totient is φ = 5043202560.

The previous prime is 20510251319. The next prime is 20510251367. The reversal of 20510251320 is 2315201502.

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, 1539327 + ... + 1552593.

It is an arithmetic number, because the mean of its divisors is an integer number (518248080).

Almost surely, 2^20510251320 is an apocalyptic number.

20510251320 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 20510251320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33167877120).

20510251320 is an abundant number, since it is smaller than the sum of its proper divisors (45825502920).

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

20510251320 is a wasteful number, since it uses less digits than its factorization.

20510251320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14285 (or 14281 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

Adding to 20510251320 its reverse (2315201502), we get a palindrome (22825452822).

The spelling of 20510251320 in words is "twenty billion, five hundred ten million, two hundred fifty-one thousand, three hundred twenty".