81690675 has 48 divisors (see below), whose sum is σ = 149240448. Its totient is φ = 39097600.

The previous prime is 81690659. The next prime is 81690689. The reversal of 81690675 is 57609618.

It is not a de Polignac number, because 81690675 - 2⁴ = 81690659 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67879 + ... + 69071.

It is an arithmetic number, because the mean of its divisors is an integer number (3109176).

Almost surely, 2^81690675 is an apocalyptic number.

81690675 is a deficient number, since it is larger than the sum of its proper divisors (67549773).

81690675 is a wasteful number, since it uses less digits than its factorization.

81690675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300 (or 1295 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 81690675 is about 9038.2893846126. The cubic root of 81690675 is about 433.9011770011.

The spelling of 81690675 in words is "eighty-one million, six hundred ninety thousand, six hundred seventy-five".