81364959 has 16 divisors (see below), whose sum is σ = 129813600. Its totient is φ = 50070528.

The previous prime is 81364949. The next prime is 81364979. The reversal of 81364959 is 95946318.

It is a happy number.

It is not a de Polignac number, because 81364959 - 2⁷ = 81364831 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81364919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115554 + ... + 116255.

It is an arithmetic number, because the mean of its divisors is an integer number (8113350).

Almost surely, 2^81364959 is an apocalyptic number.

81364959 is a deficient number, since it is larger than the sum of its proper divisors (48448641).

81364959 is a wasteful number, since it uses less digits than its factorization.

81364959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231831 (or 231825 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 81364959 is about 9020.2527126461. The cubic root of 81364959 is about 433.3237271375.

The spelling of 81364959 in words is "eighty-one million, three hundred sixty-four thousand, nine hundred fifty-nine".