91723720 has 32 divisors (see below), whose sum is σ = 225141120. Its totient is φ = 33353920.

The previous prime is 91723651. The next prime is 91723729. The reversal of 91723720 is 2732719.

It is not an unprimeable number, because it can be changed into a prime (91723729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103792 + ... + 104671.

It is an arithmetic number, because the mean of its divisors is an integer number (7035660).

Almost surely, 2^91723720 is an apocalyptic number.

It is an amenable number.

91723720 is an abundant number, since it is smaller than the sum of its proper divisors (133417400).

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

91723720 is a wasteful number, since it uses less digits than its factorization.

91723720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208485 (or 208481 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 91723720 is about 9577.2501272547. The cubic root of 91723720 is about 450.9833967172.

The spelling of 91723720 in words is "ninety-one million, seven hundred twenty-three thousand, seven hundred twenty".