91421977 has 16 divisors (see below), whose sum is σ = 98055360. Its totient is φ = 84989952.

The previous prime is 91421963. The next prime is 91421983. The reversal of 91421977 is 77912419.

It is a cyclic number.

It is not a de Polignac number, because 91421977 - 2¹¹ = 91419929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91421917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 392253 + ... + 392485.

It is an arithmetic number, because the mean of its divisors is an integer number (6128460).

Almost surely, 2^91421977 is an apocalyptic number.

It is an amenable number.

91421977 is a deficient number, since it is larger than the sum of its proper divisors (6633383).

91421977 is a wasteful number, since it uses less digits than its factorization.

91421977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552.

The product of its digits is 31752, while the sum is 40.

The square root of 91421977 is about 9561.4840375331. The cubic root of 91421977 is about 450.4883209319.

The spelling of 91421977 in words is "ninety-one million, four hundred twenty-one thousand, nine hundred seventy-seven".