91689720 has 32 divisors (see below), whose sum is σ = 275069520. Its totient is φ = 24450560.

The previous prime is 91689709. The next prime is 91689739. The reversal of 91689720 is 2798619.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 381921 + ... + 382160.

Almost surely, 2^91689720 is an apocalyptic number.

It is an amenable number.

91689720 is an abundant number, since it is smaller than the sum of its proper divisors (183379800).

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

91689720 is a wasteful number, since it uses less digits than its factorization.

91689720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764095 (or 764091 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 91689720 is about 9575.4749229477. The cubic root of 91689720 is about 450.9276665656.

The spelling of 91689720 in words is "ninety-one million, six hundred eighty-nine thousand, seven hundred twenty".