99664278 has 16 divisors (see below), whose sum is σ = 227804160. Its totient is φ = 28475496.

The previous prime is 99664277. The next prime is 99664283. The reversal of 99664278 is 87246699.

It is a happy number.

It is a super-2 number, since 2×99664278² = 19865936618522568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 99664278.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99664277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1186438 + ... + 1186521.

It is an arithmetic number, because the mean of its divisors is an integer number (14237760).

Almost surely, 2^99664278 is an apocalyptic number.

99664278 is an abundant number, since it is smaller than the sum of its proper divisors (128139882).

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

99664278 is a wasteful number, since it uses less digits than its factorization.

99664278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2372971.

The product of its digits is 1306368, while the sum is 51.

The square root of 99664278 is about 9983.1997876432. The cubic root of 99664278 is about 463.6388731681.

The spelling of 99664278 in words is "ninety-nine million, six hundred sixty-four thousand, two hundred seventy-eight".