91672213 has 2 divisors, whose sum is σ = 91672214. Its totient is φ = 91672212.

The previous prime is 91672201. The next prime is 91672223. The reversal of 91672213 is 31227619.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84235684 + 7436529 = 9178^2 + 2727^2 .

It is an emirp because it is prime and its reverse (31227619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91672213 - 2²¹ = 89575061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91672223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45836106 + 45836107.

It is an arithmetic number, because the mean of its divisors is an integer number (45836107).

Almost surely, 2^91672213 is an apocalyptic number.

It is an amenable number.

91672213 is a deficient number, since it is larger than the sum of its proper divisors (1).

91672213 is an equidigital number, since it uses as much as digits as its factorization.

91672213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 31.

The square root of 91672213 is about 9574.5607209939. The cubic root of 91672213 is about 450.8989650813.

The spelling of 91672213 in words is "ninety-one million, six hundred seventy-two thousand, two hundred thirteen".