91683561 has 4 divisors (see below), whose sum is σ = 122244752. Its totient is φ = 61122372.

The previous prime is 91683541. The next prime is 91683583. The reversal of 91683561 is 16538619.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 91683561 - 2⁷ = 91683433 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91683541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15280591 + ... + 15280596.

It is an arithmetic number, because the mean of its divisors is an integer number (30561188).

Almost surely, 2^91683561 is an apocalyptic number.

It is an amenable number.

91683561 is a deficient number, since it is larger than the sum of its proper divisors (30561191).

91683561 is a wasteful number, since it uses less digits than its factorization.

91683561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30561190.

The product of its digits is 38880, while the sum is 39.

The square root of 91683561 is about 9575.1533146995. The cubic root of 91683561 is about 450.9175697387.

The spelling of 91683561 in words is "ninety-one million, six hundred eighty-three thousand, five hundred sixty-one".