91393668 has 18 divisors (see below), whose sum is σ = 231022974. Its totient is φ = 30464544.

The previous prime is 91393661. The next prime is 91393681. The reversal of 91393668 is 86639319.

It can be written as a sum of positive squares in only one way, i.e., 88510464 + 2883204 = 9408^2 + 1698^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (91393661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1269321 + ... + 1269392.

Almost surely, 2^91393668 is an apocalyptic number.

It is an amenable number.

91393668 is an abundant number, since it is smaller than the sum of its proper divisors (139629306).

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

91393668 is a wasteful number, since it uses less digits than its factorization.

91393668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2538723 (or 2538718 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 91393668 is about 9560.0035564847. The cubic root of 91393668 is about 450.4418179253.

The spelling of 91393668 in words is "ninety-one million, three hundred ninety-three thousand, six hundred sixty-eight".