91604281 has 4 divisors (see below), whose sum is σ = 92110564. Its totient is φ = 91098000.

The previous prime is 91604251. The next prime is 91604297. The reversal of 91604281 is 18240619.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2131600 + 89472681 = 1460^2 + 9459^2 .

It is a cyclic number.

It is not a de Polignac number, because 91604281 - 2⁷ = 91604153 is a prime.

It is a super-2 number, since 2×91604281² = 16782688595053922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91604251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 252870 + ... + 253231.

It is an arithmetic number, because the mean of its divisors is an integer number (23027641).

Almost surely, 2^91604281 is an apocalyptic number.

It is an amenable number.

91604281 is a deficient number, since it is larger than the sum of its proper divisors (506283).

91604281 is a wasteful number, since it uses less digits than its factorization.

91604281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 506282.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 91604281 is about 9571.0125378666. The cubic root of 91604281 is about 450.7875607759.

The spelling of 91604281 in words is "ninety-one million, six hundred four thousand, two hundred eighty-one".