91601569 has 4 divisors (see below), whose sum is σ = 91623060. Its totient is φ = 91580080.

The previous prime is 91601561. The next prime is 91601591. The reversal of 91601569 is 96510619.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75481344 + 16120225 = 8688^2 + 4015^2 .

It is a cyclic number.

It is not a de Polignac number, because 91601569 - 2³ = 91601561 is a prime.

It is a super-2 number, since 2×91601569² = 16781694886523522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91601561) 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, 1954 + ... + 13675.

It is an arithmetic number, because the mean of its divisors is an integer number (22905765).

Almost surely, 2^91601569 is an apocalyptic number.

It is an amenable number.

91601569 is a deficient number, since it is larger than the sum of its proper divisors (21491).

91601569 is a wasteful number, since it uses less digits than its factorization.

91601569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21490.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 91601569 is about 9570.8708590180. The cubic root of 91601569 is about 450.7831121194.

The spelling of 91601569 in words is "ninety-one million, six hundred one thousand, five hundred sixty-nine".