91408487 has 4 divisors (see below), whose sum is σ = 96219480. Its totient is φ = 86597496.

The previous prime is 91408469. The next prime is 91408489. The reversal of 91408487 is 78480419.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78480419 = 4987 ⋅15737.

It is a cyclic number.

It is not a de Polignac number, because 91408487 - 2¹⁸ = 91146343 is a prime.

It is a super-2 number, since 2×91408487² = 16711022991258338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91408489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2405468 + ... + 2405505.

It is an arithmetic number, because the mean of its divisors is an integer number (24054870).

Almost surely, 2^91408487 is an apocalyptic number.

91408487 is a deficient number, since it is larger than the sum of its proper divisors (4810993).

91408487 is a wasteful number, since it uses less digits than its factorization.

91408487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4810992.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 91408487 is about 9560.7785770825. The cubic root of 91408487 is about 450.4661621959.

The spelling of 91408487 in words is "ninety-one million, four hundred eight thousand, four hundred eighty-seven".