91729920 has 104 divisors (see below), whose sum is σ = 293696496. Its totient is φ = 24444928.

The previous prime is 91729889. The next prime is 91729969. The reversal of 91729920 is 2992719.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60694 + ... + 62186.

Almost surely, 2^91729920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91729920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146848248).

91729920 is an abundant number, since it is smaller than the sum of its proper divisors (201966576).

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

91729920 is a wasteful number, since it uses less digits than its factorization.

91729920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1525 (or 1503 counting only the distinct ones).

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

The square root of 91729920 is about 9577.5738055105. The cubic root of 91729920 is about 450.9935577895.

The spelling of 91729920 in words is "ninety-one million, seven hundred twenty-nine thousand, nine hundred twenty".