91281409 has 2 divisors, whose sum is σ = 91281410. Its totient is φ = 91281408.

The previous prime is 91281397. The next prime is 91281431. The reversal of 91281409 is 90418219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85655025 + 5626384 = 9255^2 + 2372^2 .

It is a cyclic number.

It is not a de Polignac number, because 91281409 - 2⁹ = 91280897 is a prime.

It is not a weakly prime, because it can be changed into another prime (91281469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45640704 + 45640705.

It is an arithmetic number, because the mean of its divisors is an integer number (45640705).

Almost surely, 2^91281409 is an apocalyptic number.

It is an amenable number.

91281409 is a deficient number, since it is larger than the sum of its proper divisors (1).

91281409 is an equidigital number, since it uses as much as digits as its factorization.

91281409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 91281409 is about 9554.1304680227. The cubic root of 91281409 is about 450.2573162095.

The spelling of 91281409 in words is "ninety-one million, two hundred eighty-one thousand, four hundred nine".