81866975074 has 8 divisors (see below), whose sum is σ = 123436735020. Its totient is φ = 40721396736.

The previous prime is 81866975011. The next prime is 81866975087. The reversal of 81866975074 is 47057966818.

It can be written as a sum of positive squares in 2 ways, for example, as 81001144449 + 865830625 = 284607^2 + 29425^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106044919 + ... + 106045690.

Almost surely, 2^81866975074 is an apocalyptic number.

81866975074 is a deficient number, since it is larger than the sum of its proper divisors (41569759946).

81866975074 is a wasteful number, since it uses less digits than its factorization.

81866975074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212090804.

The product of its (nonzero) digits is 20321280, while the sum is 61.

The spelling of 81866975074 in words is "eighty-one billion, eight hundred sixty-six million, nine hundred seventy-five thousand, seventy-four".