91801690 has 16 divisors (see below), whose sum is σ = 165372192. Its totient is φ = 36691984.

The previous prime is 91801687. The next prime is 91801691. The reversal of 91801690 is 9610819.

It is a super-2 number, since 2×91801690² = 16855100573712200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91801691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13917 + ... + 19423.

It is an arithmetic number, because the mean of its divisors is an integer number (10335762).

Almost surely, 2^91801690 is an apocalyptic number.

91801690 is a deficient number, since it is larger than the sum of its proper divisors (73570502).

91801690 is a wasteful number, since it uses less digits than its factorization.

91801690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7181.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 91801690 is about 9581.3198464512. The cubic root of 91801690 is about 451.1111470840. Note that the first 4 decimals are identical.

The spelling of 91801690 in words is "ninety-one million, eight hundred one thousand, six hundred ninety".