91505641 has 2 divisors, whose sum is σ = 91505642. Its totient is φ = 91505640.

The previous prime is 91505639. The next prime is 91505647. The reversal of 91505641 is 14650519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84107241 + 7398400 = 9171^2 + 2720^2 .

It is a cyclic number.

It is not a de Polignac number, because 91505641 - 2¹ = 91505639 is a prime.

Together with 91505639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (91505647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45752820 + 45752821.

It is an arithmetic number, because the mean of its divisors is an integer number (45752821).

Almost surely, 2^91505641 is an apocalyptic number.

It is an amenable number.

91505641 is a deficient number, since it is larger than the sum of its proper divisors (1).

91505641 is an equidigital number, since it uses as much as digits as its factorization.

91505641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 91505641 is about 9565.8580901036. The cubic root of 91505641 is about 450.6256991454.

The spelling of 91505641 in words is "ninety-one million, five hundred five thousand, six hundred forty-one".