813920520 has 128 divisors (see below), whose sum is σ = 2858768640. Its totient is φ = 181493760.

The previous prime is 813920507. The next prime is 813920551. The reversal of 813920520 is 25029318.

It is a happy number.

It is a super-2 number, since 2×813920520² = 1324933225754140800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 22624 + ... + 46256.

It is an arithmetic number, because the mean of its divisors is an integer number (22334130).

Almost surely, 2^813920520 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 813920520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1429384320).

813920520 is an abundant number, since it is smaller than the sum of its proper divisors (2044848120).

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

813920520 is a wasteful number, since it uses less digits than its factorization.

813920520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23695 (or 23691 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 813920520 is about 28529.2923150926. The cubic root of 813920520 is about 933.6712784144.

Adding to 813920520 its reverse (25029318), we get a palindrome (838949838).

The spelling of 813920520 in words is "eight hundred thirteen million, nine hundred twenty thousand, five hundred twenty".