91291961 has 2 divisors, whose sum is σ = 91291962. Its totient is φ = 91291960.

The previous prime is 91291951. The next prime is 91291973. The reversal of 91291961 is 16919219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70644025 + 20647936 = 8405^2 + 4544^2 .

It is a cyclic number.

It is not a de Polignac number, because 91291961 - 2¹⁰ = 91290937 is a prime.

It is equal to p_5287664 and since 91291961 and 5287664 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (91291951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45645980 + 45645981.

It is an arithmetic number, because the mean of its divisors is an integer number (45645981).

Almost surely, 2^91291961 is an apocalyptic number.

It is an amenable number.

91291961 is a deficient number, since it is larger than the sum of its proper divisors (1).

91291961 is an equidigital number, since it uses as much as digits as its factorization.

91291961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 38.

The square root of 91291961 is about 9554.6826739563. The cubic root of 91291961 is about 450.2746652410.

The spelling of 91291961 in words is "ninety-one million, two hundred ninety-one thousand, nine hundred sixty-one".