91144728 has 24 divisors (see below), whose sum is σ = 246850500. Its totient is φ = 30381552.

The previous prime is 91144687. The next prime is 91144777. The reversal of 91144728 is 82744119.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×91144728² = 16614722884387968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 91144692 and 91144701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 632878 + ... + 633021.

Almost surely, 2^91144728 is an apocalyptic number.

It is an amenable number.

91144728 is an abundant number, since it is smaller than the sum of its proper divisors (155705772).

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

91144728 is a wasteful number, since it uses less digits than its factorization.

91144728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1265911 (or 1265904 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 91144728 is about 9546.9748088072. The cubic root of 91144728 is about 450.0324717309.

The spelling of 91144728 in words is "ninety-one million, one hundred forty-four thousand, seven hundred twenty-eight".