91298640 has 80 divisors (see below), whose sum is σ = 284946048. Its totient is φ = 24181248.

The previous prime is 91298633. The next prime is 91298671. The reversal of 91298640 is 4689219.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36469 + ... + 38891.

Almost surely, 2^91298640 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 91298640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142473024).

91298640 is an abundant number, since it is smaller than the sum of its proper divisors (193647408).

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

91298640 is a wasteful number, since it uses less digits than its factorization.

91298640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2596 (or 2590 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 91298640 is about 9555.0321820494. The cubic root of 91298640 is about 450.2856458032.

The spelling of 91298640 in words is "ninety-one million, two hundred ninety-eight thousand, six hundred forty".