81764425 has 24 divisors (see below), whose sum is σ = 107832384. Its totient is φ = 61364160.

The previous prime is 81764393. The next prime is 81764479. The reversal of 81764425 is 52446718.

It is not a de Polignac number, because 81764425 - 2⁵ = 81764393 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29134 + ... + 31816.

It is an arithmetic number, because the mean of its divisors is an integer number (4493016).

Almost surely, 2^81764425 is an apocalyptic number.

It is an amenable number.

81764425 is a deficient number, since it is larger than the sum of its proper divisors (26067959).

81764425 is a wasteful number, since it uses less digits than its factorization.

81764425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2769 (or 2764 counting only the distinct ones).

The product of its digits is 53760, while the sum is 37.

The square root of 81764425 is about 9042.3683291492. The cubic root of 81764425 is about 434.0317124498.

The spelling of 81764425 in words is "eighty-one million, seven hundred sixty-four thousand, four hundred twenty-five".