91744381 has 2 divisors, whose sum is σ = 91744382. Its totient is φ = 91744380.

The previous prime is 91744343. The next prime is 91744399. The reversal of 91744381 is 18344719.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76212900 + 15531481 = 8730^2 + 3941^2 .

It is an emirp because it is prime and its reverse (18344719) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91744381 - 2⁷ = 91744253 is a prime.

It is a super-2 number, since 2×91744381² = 16834062890146322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91744381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91744321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45872190 + 45872191.

It is an arithmetic number, because the mean of its divisors is an integer number (45872191).

Almost surely, 2^91744381 is an apocalyptic number.

It is an amenable number.

91744381 is a deficient number, since it is larger than the sum of its proper divisors (1).

91744381 is an equidigital number, since it uses as much as digits as its factorization.

91744381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 37.

The square root of 91744381 is about 9578.3287164306. The cubic root of 91744381 is about 451.0172558921.

The spelling of 91744381 in words is "ninety-one million, seven hundred forty-four thousand, three hundred eighty-one".