81465641 has 2 divisors, whose sum is σ = 81465642. Its totient is φ = 81465640.

The previous prime is 81465599. The next prime is 81465653. The reversal of 81465641 is 14656418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48930025 + 32535616 = 6995^2 + 5704^2 .

It is a cyclic number.

It is not a de Polignac number, because 81465641 - 2⁶ = 81465577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81465661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40732820 + 40732821.

It is an arithmetic number, because the mean of its divisors is an integer number (40732821).

Almost surely, 2^81465641 is an apocalyptic number.

It is an amenable number.

81465641 is a deficient number, since it is larger than the sum of its proper divisors (1).

81465641 is an equidigital number, since it uses as much as digits as its factorization.

81465641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 35.

The square root of 81465641 is about 9025.8318730187. The cubic root of 81465641 is about 433.5023868339.

The spelling of 81465641 in words is "eighty-one million, four hundred sixty-five thousand, six hundred forty-one".