989991825 has 12 divisors (see below), whose sum is σ = 1636786608. Its totient is φ = 527995600.

The previous prime is 989991817. The next prime is 989991833. The reversal of 989991825 is 528199989.

It is an interprime number because it is at equal distance from previous prime (989991817) and next prime (989991833).

It is not a de Polignac number, because 989991825 - 2³ = 989991817 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6599871 + ... + 6600020.

It is an arithmetic number, because the mean of its divisors is an integer number (136398884).

Almost surely, 2^989991825 is an apocalyptic number.

It is an amenable number.

989991825 is a deficient number, since it is larger than the sum of its proper divisors (646794783).

989991825 is a wasteful number, since it uses less digits than its factorization.

989991825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13199904 (or 13199899 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 60.

The square root of 989991825 is about 31464.1355355586. The cubic root of 989991825 is about 996.6527500856.

The spelling of 989991825 in words is "nine hundred eighty-nine million, nine hundred ninety-one thousand, eight hundred twenty-five".