91534981 has 2 divisors, whose sum is σ = 91534982. Its totient is φ = 91534980.

The previous prime is 91534979. The next prime is 91535023. The reversal of 91534981 is 18943519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89132481 + 2402500 = 9441^2 + 1550^2 .

It is a cyclic number.

It is not a de Polignac number, because 91534981 - 2¹ = 91534979 is a prime.

It is a super-2 number, since 2×91534981² = 16757305493340722, which contains 22 as substring.

Together with 91534979, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91534921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45767490 + 45767491.

It is an arithmetic number, because the mean of its divisors is an integer number (45767491).

Almost surely, 2^91534981 is an apocalyptic number.

It is an amenable number.

91534981 is a deficient number, since it is larger than the sum of its proper divisors (1).

91534981 is an equidigital number, since it uses as much as digits as its factorization.

91534981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 40.

The square root of 91534981 is about 9567.3915462889. The cubic root of 91534981 is about 450.6738562682.

The spelling of 91534981 in words is "ninety-one million, five hundred thirty-four thousand, nine hundred eighty-one".