91985649 has 32 divisors (see below), whose sum is σ = 146227200. Its totient is φ = 50328000.

The previous prime is 91985639. The next prime is 91985693. The reversal of 91985649 is 94658919.

It is not a de Polignac number, because 91985649 - 2⁴ = 91985633 is a prime.

It is a super-2 number, since 2×91985649² = 16922719243902402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91985609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 65052 + ... + 66450.

It is an arithmetic number, because the mean of its divisors is an integer number (4569600).

Almost surely, 2^91985649 is an apocalyptic number.

It is an amenable number.

91985649 is a deficient number, since it is larger than the sum of its proper divisors (54241551).

91985649 is a wasteful number, since it uses less digits than its factorization.

91985649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1541.

The product of its digits is 699840, while the sum is 51.

The square root of 91985649 is about 9590.9149198604. The cubic root of 91985649 is about 451.4122693038.

It can be divided in two parts, 919 and 85649, that added together give a palindrome (86568).

The spelling of 91985649 in words is "ninety-one million, nine hundred eighty-five thousand, six hundred forty-nine".