91478531 has 2 divisors, whose sum is σ = 91478532. Its totient is φ = 91478530.

The previous prime is 91478461. The next prime is 91478549. The reversal of 91478531 is 13587419.

It is a strong prime.

It is an emirp because it is prime and its reverse (13587419) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91478531 is a prime.

It is a super-2 number, since 2×91478531² = 16736643267835922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91472531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45739265 + 45739266.

It is an arithmetic number, because the mean of its divisors is an integer number (45739266).

Almost surely, 2^91478531 is an apocalyptic number.

91478531 is a deficient number, since it is larger than the sum of its proper divisors (1).

91478531 is an equidigital number, since it uses as much as digits as its factorization.

91478531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 91478531 is about 9564.4409664130. The cubic root of 91478531 is about 450.5811930756.

The spelling of 91478531 in words is "ninety-one million, four hundred seventy-eight thousand, five hundred thirty-one".