91229381 has 4 divisors (see below), whose sum is σ = 91248492. Its totient is φ = 91210272.

The previous prime is 91229357. The next prime is 91229401. The reversal of 91229381 is 18392219.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 54626881 + 36602500 = 7391^2 + 6050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91229381 is a prime.

It is a super-2 number, since 2×91229381² = 16645599915286322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91229351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4385 + ... + 14201.

It is an arithmetic number, because the mean of its divisors is an integer number (22812123).

Almost surely, 2^91229381 is an apocalyptic number.

It is an amenable number.

91229381 is a deficient number, since it is larger than the sum of its proper divisors (19111).

91229381 is an equidigital number, since it uses as much as digits as its factorization.

91229381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19110.

The product of its digits is 7776, while the sum is 35.

The square root of 91229381 is about 9551.4072785114. The cubic root of 91229381 is about 450.1717550127.

The spelling of 91229381 in words is "ninety-one million, two hundred twenty-nine thousand, three hundred eighty-one".