81342975 has 48 divisors (see below), whose sum is σ = 157489920. Its totient is φ = 36268800.

The previous prime is 81342959. The next prime is 81342991. The reversal of 81342975 is 57924318.

It is an interprime number because it is at equal distance from previous prime (81342959) and next prime (81342991).

It is not a de Polignac number, because 81342975 - 2⁴ = 81342959 is a prime.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 19636 + ... + 23414.

It is an arithmetic number, because the mean of its divisors is an integer number (3281040).

Almost surely, 2^81342975 is an apocalyptic number.

81342975 is a deficient number, since it is larger than the sum of its proper divisors (76146945).

81342975 is a wasteful number, since it uses less digits than its factorization.

81342975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3840 (or 3835 counting only the distinct ones).

The product of its digits is 60480, while the sum is 39.

The square root of 81342975 is about 9019.0340391862. The cubic root of 81342975 is about 433.2846970397.

The spelling of 81342975 in words is "eighty-one million, three hundred forty-two thousand, nine hundred seventy-five".