99666431 has 4 divisors (see below), whose sum is σ = 99703032. Its totient is φ = 99629832.

The previous prime is 99666407. The next prime is 99666443. The reversal of 99666431 is 13466699.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 99666431 - 2²² = 95472127 is a prime.

It is a super-2 number, since 2×99666431² = 19866794936555522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99666451) 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, 13856 + ... + 19781.

It is an arithmetic number, because the mean of its divisors is an integer number (24925758).

Almost surely, 2^99666431 is an apocalyptic number.

99666431 is a deficient number, since it is larger than the sum of its proper divisors (36601).

99666431 is a wasteful number, since it uses less digits than its factorization.

99666431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36600.

The product of its digits is 209952, while the sum is 44.

The square root of 99666431 is about 9983.3076182195. The cubic root of 99666431 is about 463.6422117340.

The spelling of 99666431 in words is "ninety-nine million, six hundred sixty-six thousand, four hundred thirty-one".