91408531 has 2 divisors, whose sum is σ = 91408532. Its totient is φ = 91408530.

The previous prime is 91408511. The next prime is 91408547. The reversal of 91408531 is 13580419.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91408531 - 2⁷ = 91408403 is a prime.

It is a super-2 number, since 2×91408531² = 16711039079155922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 91408493 and 91408502.

It is not a weakly prime, because it can be changed into another prime (91408501) 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 as a sum of consecutive naturals, namely, 45704265 + 45704266.

It is an arithmetic number, because the mean of its divisors is an integer number (45704266).

Almost surely, 2^91408531 is an apocalyptic number.

91408531 is a deficient number, since it is larger than the sum of its proper divisors (1).

91408531 is an equidigital number, since it uses as much as digits as its factorization.

91408531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 91408531 is about 9560.7808781501. The cubic root of 91408531 is about 450.4662344740.

It can be divided in two parts, 9140 and 8531, that added together give a palindrome (17671).

The spelling of 91408531 in words is "ninety-one million, four hundred eight thousand, five hundred thirty-one".