991513215 has 96 divisors (see below), whose sum is σ = 2178289152. Its totient is φ = 405216000.

The previous prime is 991513183. The next prime is 991513217. The reversal of 991513215 is 512315199.

It is not a de Polignac number, because 991513215 - 2⁵ = 991513183 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 991513215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991513217) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 209020 + ... + 213710.

It is an arithmetic number, because the mean of its divisors is an integer number (22690512).

Almost surely, 2^991513215 is an apocalyptic number.

991513215 is an abundant number, since it is smaller than the sum of its proper divisors (1186775937).

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

991513215 is a wasteful number, since it uses less digits than its factorization.

991513215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4781 (or 4778 counting only the distinct ones).

The product of its digits is 12150, while the sum is 36.

The square root of 991513215 is about 31488.3028281932. The cubic root of 991513215 is about 997.1630308839.

The spelling of 991513215 in words is "nine hundred ninety-one million, five hundred thirteen thousand, two hundred fifteen".