81964375 has 10 divisors (see below), whose sum is σ = 102423464. Its totient is φ = 65571000.

The previous prime is 81964369. The next prime is 81964391. The reversal of 81964375 is 57346918.

It is not a de Polignac number, because 81964375 - 2⁹ = 81963863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 64947 + ... + 66196.

Almost surely, 2^81964375 is an apocalyptic number.

81964375 is a deficient number, since it is larger than the sum of its proper divisors (20459089).

81964375 is an equidigital number, since it uses as much as digits as its factorization.

81964375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131163 (or 131148 counting only the distinct ones).

The product of its digits is 181440, while the sum is 43.

The square root of 81964375 is about 9053.4178628847. The cubic root of 81964375 is about 434.3852239541.

The spelling of 81964375 in words is "eighty-one million, nine hundred sixty-four thousand, three hundred seventy-five".