91287072 has 54 divisors (see below), whose sum is σ = 260059527. Its totient is φ = 30374976.

The previous prime is 91287061. The next prime is 91287109. The reversal of 91287072 is 27078219.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 45643536 + 45643536 = 6756^2 + 6756^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=6756.

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

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 161863 + ... + 162425.

Almost surely, 2^91287072 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 91287072

91287072 is an abundant number, since it is smaller than the sum of its proper divisors (168772455).

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

91287072 is an equidigital number, since it uses as much as digits as its factorization.

91287072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142 (or 568 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 91287072 is about 9554.4268273926. The cubic root of 91287072 is about 450.2666271761.

Multiplying 91287072 by its product of nonzero digits (14112), we get a square (1288243160064 = 1135008²).

The spelling of 91287072 in words is "ninety-one million, two hundred eighty-seven thousand, seventy-two".