91601918 has 4 divisors (see below), whose sum is σ = 137402880. Its totient is φ = 45800958.

The previous prime is 91601897. The next prime is 91601921. The reversal of 91601918 is 81910619.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81910619 = 7 ⋅11701517.

It is a super-2 number, since 2×91601918² = 16781822762557448, which contains 22 as substring.

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, 22900478 + ... + 22900481.

It is an arithmetic number, because the mean of its divisors is an integer number (34350720).

Almost surely, 2^91601918 is an apocalyptic number.

91601918 is a deficient number, since it is larger than the sum of its proper divisors (45800962).

91601918 is a wasteful number, since it uses less digits than its factorization.

91601918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45800961.

The product of its (nonzero) digits is 3888, while the sum is 35.

The square root of 91601918 is about 9570.8890914063. The cubic root of 91601918 is about 450.7836846100.

The spelling of 91601918 in words is "ninety-one million, six hundred one thousand, nine hundred eighteen".