91770720 has 48 divisors (see below), whose sum is σ = 289079280. Its totient is φ = 24472064.

The previous prime is 91770691. The next prime is 91770727. The reversal of 91770720 is 2707719.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91770727) 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, 95115 + ... + 96074.

It is an arithmetic number, because the mean of its divisors is an integer number (6022485).

Almost surely, 2^91770720 is an apocalyptic number.

It is an amenable number.

91770720 is an abundant number, since it is smaller than the sum of its proper divisors (197308560).

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

91770720 is a wasteful number, since it uses less digits than its factorization.

91770720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191207 (or 191199 counting only the distinct ones).

The product of its (nonzero) digits is 6174, while the sum is 33.

The square root of 91770720 is about 9579.7035444736. The cubic root of 91770720 is about 451.0604127835.

The spelling of 91770720 in words is "ninety-one million, seven hundred seventy thousand, seven hundred twenty".