91572137 has 2 divisors, whose sum is σ = 91572138. Its totient is φ = 91572136.

The previous prime is 91572119. The next prime is 91572197. The reversal of 91572137 is 73127519.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70375321 + 21196816 = 8389^2 + 4604^2 .

It is an emirp because it is prime and its reverse (73127519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91572137 - 2¹⁴ = 91555753 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91572097 and 91572106.

It is not a weakly prime, because it can be changed into another prime (91572197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45786068 + 45786069.

It is an arithmetic number, because the mean of its divisors is an integer number (45786069).

Almost surely, 2^91572137 is an apocalyptic number.

It is an amenable number.

91572137 is a deficient number, since it is larger than the sum of its proper divisors (1).

91572137 is an equidigital number, since it uses as much as digits as its factorization.

91572137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13230, while the sum is 35.

The square root of 91572137 is about 9569.3331533603. Note that the first 3 decimals coincide. The cubic root of 91572137 is about 450.7348273942.

The spelling of 91572137 in words is "ninety-one million, five hundred seventy-two thousand, one hundred thirty-seven".