91337252821 has 2 divisors, whose sum is σ = 91337252822. Its totient is φ = 91337252820.

The previous prime is 91337252761. The next prime is 91337252869. The reversal of 91337252821 is 12825273319.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51051143025 + 40286109796 = 225945^2 + 200714^2 .

It is a cyclic number.

It is not a de Polignac number, because 91337252821 - 2¹⁷ = 91337121749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91337252021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45668626410 + 45668626411.

It is an arithmetic number, because the mean of its divisors is an integer number (45668626411).

Almost surely, 2^91337252821 is an apocalyptic number.

It is an amenable number.

91337252821 is a deficient number, since it is larger than the sum of its proper divisors (1).

91337252821 is an equidigital number, since it uses as much as digits as its factorization.

91337252821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 43.

The spelling of 91337252821 in words is "ninety-one billion, three hundred thirty-seven million, two hundred fifty-two thousand, eight hundred twenty-one".