81766075 has 6 divisors (see below), whose sum is σ = 101389964. Its totient is φ = 65412840.

The previous prime is 81766049. The next prime is 81766079. The reversal of 81766075 is 57066718.

It is not a de Polignac number, because 81766075 - 2²³ = 73377467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81766079) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1635297 + ... + 1635346.

Almost surely, 2^81766075 is an apocalyptic number.

81766075 is a deficient number, since it is larger than the sum of its proper divisors (19623889).

81766075 is a wasteful number, since it uses less digits than its factorization.

81766075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3270653 (or 3270648 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 81766075 is about 9042.4595658482. The cubic root of 81766075 is about 434.0346320060.

The spelling of 81766075 in words is "eighty-one million, seven hundred sixty-six thousand, seventy-five".