9999999520 has 48 divisors (see below), whose sum is σ = 27000001728. Its totient is φ = 3428570880.

The previous prime is 9999999511. The next prime is 9999999557. The reversal of 9999999520 is 259999999.

It is a Harshad number since it is a multiple of its sum of digits (70).

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 9999999520.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4463166 + ... + 4465405.

It is an arithmetic number, because the mean of its divisors is an integer number (562500036).

Almost surely, 2^9999999520 is an apocalyptic number.

It is an amenable number.

9999999520 is an abundant number, since it is smaller than the sum of its proper divisors (17000002208).

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

9999999520 is a wasteful number, since it uses less digits than its factorization.

9999999520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8928593 (or 8928585 counting only the distinct ones).

The product of its (nonzero) digits is 47829690, while the sum is 70.

The square root of 9999999520 is about 99999.9976000000. The cubic root of 9999999520 is about 2154.4346555609.

The spelling of 9999999520 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, five hundred twenty".