91390649 has 4 divisors (see below), whose sum is σ = 104446464. Its totient is φ = 78334836.

The previous prime is 91390643. The next prime is 91390667. The reversal of 91390649 is 94609319.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94609319 = 7 ⋅13515617.

It is a cyclic number.

It is not a de Polignac number, because 91390649 - 2¹² = 91386553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91390643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6527897 + ... + 6527910.

It is an arithmetic number, because the mean of its divisors is an integer number (26111616).

Almost surely, 2^91390649 is an apocalyptic number.

It is an amenable number.

91390649 is a deficient number, since it is larger than the sum of its proper divisors (13055815).

91390649 is a wasteful number, since it uses less digits than its factorization.

91390649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13055814.

The product of its (nonzero) digits is 52488, while the sum is 41.

The square root of 91390649 is about 9559.8456577499. The cubic root of 91390649 is about 450.4368580674.

The spelling of 91390649 in words is "ninety-one million, three hundred ninety thousand, six hundred forty-nine".