91978633 has 16 divisors (see below), whose sum is σ = 101998080. Its totient is φ = 82627776.

The previous prime is 91978609. The next prime is 91978651. The reversal of 91978633 is 33687919.

It is not a de Polignac number, because 91978633 - 2¹³ = 91970441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91978693) 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 15 ways as a sum of consecutive naturals, for example, 22816 + ... + 26542.

It is an arithmetic number, because the mean of its divisors is an integer number (6374880).

Almost surely, 2^91978633 is an apocalyptic number.

It is an amenable number.

91978633 is a deficient number, since it is larger than the sum of its proper divisors (10019447).

91978633 is a wasteful number, since it uses less digits than its factorization.

91978633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3816.

The product of its digits is 244944, while the sum is 46.

The square root of 91978633 is about 9590.5491500748. The cubic root of 91978633 is about 451.4007921910.

The spelling of 91978633 in words is "ninety-one million, nine hundred seventy-eight thousand, six hundred thirty-three".