91697213 has 4 divisors (see below), whose sum is σ = 93200508. Its totient is φ = 90193920.

The previous prime is 91697209. The next prime is 91697219. The reversal of 91697213 is 31279619.

It is a happy number.

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 32684089 + 59013124 = 5717^2 + 7682^2 .

It is a cyclic number.

It is not a de Polignac number, because 91697213 - 2² = 91697209 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91697219) 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, 751556 + ... + 751677.

It is an arithmetic number, because the mean of its divisors is an integer number (23300127).

Almost surely, 2^91697213 is an apocalyptic number.

It is an amenable number.

91697213 is a deficient number, since it is larger than the sum of its proper divisors (1503295).

91697213 is a wasteful number, since it uses less digits than its factorization.

91697213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503294.

The product of its digits is 20412, while the sum is 38.

The square root of 91697213 is about 9575.8661749212. The cubic root of 91697213 is about 450.9399496909.

The spelling of 91697213 in words is "ninety-one million, six hundred ninety-seven thousand, two hundred thirteen".