99991515 has 32 divisors (see below), whose sum is σ = 174033216. Its totient is φ = 48729600.

The previous prime is 99991499. The next prime is 99991517. The reversal of 99991515 is 51519999.

It is a happy number.

It is not a de Polignac number, because 99991515 - 2⁴ = 99991499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (99991517) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17157 + ... + 22233.

It is an arithmetic number, because the mean of its divisors is an integer number (5438538).

Almost surely, 2^99991515 is an apocalyptic number.

99991515 is a deficient number, since it is larger than the sum of its proper divisors (74041701).

99991515 is a wasteful number, since it uses less digits than its factorization.

99991515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5199.

The product of its digits is 164025, while the sum is 48.

The square root of 99991515 is about 9999.5757410002. The cubic root of 99991515 is about 464.1457550295.

The spelling of 99991515 in words is "ninety-nine million, nine hundred ninety-one thousand, five hundred fifteen".