81375089 has 2 divisors, whose sum is σ = 81375090. Its totient is φ = 81375088.

The previous prime is 81375079. The next prime is 81375097. The reversal of 81375089 is 98057318.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80550625 + 824464 = 8975^2 + 908^2 .

It is a cyclic number.

It is not a de Polignac number, because 81375089 - 2⁸ = 81374833 is a prime.

It is not a weakly prime, because it can be changed into another prime (81375059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40687544 + 40687545.

It is an arithmetic number, because the mean of its divisors is an integer number (40687545).

Almost surely, 2^81375089 is an apocalyptic number.

It is an amenable number.

81375089 is a deficient number, since it is larger than the sum of its proper divisors (1).

81375089 is an equidigital number, since it uses as much as digits as its factorization.

81375089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 81375089 is about 9020.8142093716. The cubic root of 81375089 is about 433.3417094370.

The spelling of 81375089 in words is "eighty-one million, three hundred seventy-five thousand, eighty-nine".