91421558 has 4 divisors (see below), whose sum is σ = 137132340. Its totient is φ = 45710778.

The previous prime is 91421537. The next prime is 91421581. The reversal of 91421558 is 85512419.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22855388 + ... + 22855391.

It is an arithmetic number, because the mean of its divisors is an integer number (34283085).

Almost surely, 2^91421558 is an apocalyptic number.

91421558 is a deficient number, since it is larger than the sum of its proper divisors (45710782).

91421558 is a wasteful number, since it uses less digits than its factorization.

91421558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45710781.

The product of its digits is 14400, while the sum is 35.

The square root of 91421558 is about 9561.4621266833. The cubic root of 91421558 is about 450.4876327134.

The spelling of 91421558 in words is "ninety-one million, four hundred twenty-one thousand, five hundred fifty-eight".