91981349 has 4 divisors (see below), whose sum is σ = 92002560. Its totient is φ = 91960140.

The previous prime is 91981319. The next prime is 91981363. The reversal of 91981349 is 94318919.

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.

It is a cyclic number.

It is not a de Polignac number, because 91981349 - 2⁸ = 91981093 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91981319) 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, 1487 + ... + 13644.

It is an arithmetic number, because the mean of its divisors is an integer number (23000640).

Almost surely, 2^91981349 is an apocalyptic number.

It is an amenable number.

91981349 is a deficient number, since it is larger than the sum of its proper divisors (21211).

91981349 is a wasteful number, since it uses less digits than its factorization.

91981349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21210.

The product of its digits is 69984, while the sum is 44.

The square root of 91981349 is about 9590.6907467606. The cubic root of 91981349 is about 451.4052352246.

The spelling of 91981349 in words is "ninety-one million, nine hundred eighty-one thousand, three hundred forty-nine".