91442261 has 2 divisors, whose sum is σ = 91442262. Its totient is φ = 91442260.

The previous prime is 91442251. The next prime is 91442287. The reversal of 91442261 is 16224419.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47472100 + 43970161 = 6890^2 + 6631^2 .

It is an emirp because it is prime and its reverse (16224419) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91442261 - 2²² = 87247957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91442251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45721130 + 45721131.

It is an arithmetic number, because the mean of its divisors is an integer number (45721131).

Almost surely, 2^91442261 is an apocalyptic number.

91442261 is the 4277-th centered decagonal number.

It is an amenable number.

91442261 is a deficient number, since it is larger than the sum of its proper divisors (1).

91442261 is an equidigital number, since it uses as much as digits as its factorization.

91442261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 91442261 is about 9562.5446927060. The cubic root of 91442261 is about 450.5216354211.

The spelling of 91442261 in words is "ninety-one million, four hundred forty-two thousand, two hundred sixty-one".