91431658 has 16 divisors (see below), whose sum is σ = 140063040. Its totient is φ = 44754336.

The previous prime is 91431653. The next prime is 91431671. The reversal of 91431658 is 85613419.

It is not an unprimeable number, because it can be changed into a prime (91431653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15841 + ... + 20827.

It is an arithmetic number, because the mean of its divisors is an integer number (8753940).

Almost surely, 2^91431658 is an apocalyptic number.

91431658 is a deficient number, since it is larger than the sum of its proper divisors (48631382).

91431658 is a wasteful number, since it uses less digits than its factorization.

91431658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5181.

The product of its digits is 25920, while the sum is 37.

The square root of 91431658 is about 9561.9902739963. The cubic root of 91431658 is about 450.5042216437.

It can be divided in two parts, 9143 and 1658, that added together give a palindrome (10801).

The spelling of 91431658 in words is "ninety-one million, four hundred thirty-one thousand, six hundred fifty-eight".