99997815 has 16 divisors (see below), whose sum is σ = 160354656. Its totient is φ = 53212800.

The previous prime is 99997789. The next prime is 99997837. The reversal of 99997815 is 51879999.

It is not a de Polignac number, because 99997815 - 2⁵ = 99997783 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 316 + ... + 14145.

It is an arithmetic number, because the mean of its divisors is an integer number (10022166).

Almost surely, 2^99997815 is an apocalyptic number.

99997815 is a deficient number, since it is larger than the sum of its proper divisors (60356841).

99997815 is a wasteful number, since it uses less digits than its factorization.

99997815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14930.

The product of its digits is 1837080, while the sum is 57.

The square root of 99997815 is about 9999.8907494032. The cubic root of 99997815 is about 464.1555027128.

The spelling of 99997815 in words is "ninety-nine million, nine hundred ninety-seven thousand, eight hundred fifteen".