91920729 has 8 divisors (see below), whose sum is σ = 125550432. Its totient is φ = 59785760.

The previous prime is 91920721. The next prime is 91920733. The reversal of 91920729 is 92702919.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91920729 - 2³ = 91920721 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91920721) 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, 373539 + ... + 373784.

It is an arithmetic number, because the mean of its divisors is an integer number (15693804).

Almost surely, 2^91920729 is an apocalyptic number.

It is an amenable number.

91920729 is a deficient number, since it is larger than the sum of its proper divisors (33629703).

91920729 is a wasteful number, since it uses less digits than its factorization.

91920729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747367.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 91920729 is about 9587.5298695754. The cubic root of 91920729 is about 451.3060477289.

The spelling of 91920729 in words is "ninety-one million, nine hundred twenty thousand, seven hundred twenty-nine".