991345825 has 12 divisors (see below), whose sum is σ = 1231116268. Its totient is φ = 791884800.

The previous prime is 991345819. The next prime is 991345829. The reversal of 991345825 is 528543199.

It can be written as a sum of positive squares in 6 ways, for example, as 119443041 + 871902784 = 10929^2 + 29528^2 .

It is not a de Polignac number, because 991345825 - 2¹¹ = 991343777 is a prime.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991345829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12636 + ... + 46285.

Almost surely, 2^991345825 is an apocalyptic number.

It is an amenable number.

991345825 is a deficient number, since it is larger than the sum of its proper divisors (239770443).

991345825 is a wasteful number, since it uses less digits than its factorization.

991345825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59604 (or 59599 counting only the distinct ones).

The product of its digits is 388800, while the sum is 46.

The square root of 991345825 is about 31485.6447448675. The cubic root of 991345825 is about 997.1069131200.

The spelling of 991345825 in words is "nine hundred ninety-one million, three hundred forty-five thousand, eight hundred twenty-five".