99661579 has 4 divisors (see below), whose sum is σ = 99922176. Its totient is φ = 99400984.

The previous prime is 99661567. The next prime is 99661589. The reversal of 99661579 is 97516699.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97516699 = 7 ⋅13930957.

It is a cyclic number.

It is not a de Polignac number, because 99661579 - 2⁵ = 99661547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99661589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129724 + ... + 130489.

It is an arithmetic number, because the mean of its divisors is an integer number (24980544).

Almost surely, 2^99661579 is an apocalyptic number.

99661579 is a deficient number, since it is larger than the sum of its proper divisors (260597).

99661579 is a wasteful number, since it uses less digits than its factorization.

99661579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260596.

The product of its digits is 918540, while the sum is 52.

The square root of 99661579 is about 9983.0646096276. The cubic root of 99661579 is about 463.6346878751.

The spelling of 99661579 in words is "ninety-nine million, six hundred sixty-one thousand, five hundred seventy-nine".