81694994 has 8 divisors (see below), whose sum is σ = 122640588. Its totient is φ = 40814800.

The previous prime is 81694993. The next prime is 81695023. The reversal of 81694994 is 49949618.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 68641225 + 13053769 = 8285^2 + 3613^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81694993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13097 + ... + 18300.

Almost surely, 2^81694994 is an apocalyptic number.

81694994 is a deficient number, since it is larger than the sum of its proper divisors (40945594).

81694994 is a wasteful number, since it uses less digits than its factorization.

81694994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32700.

The product of its digits is 559872, while the sum is 50.

The square root of 81694994 is about 9038.5283094097. The cubic root of 81694994 is about 433.9088236762.

The spelling of 81694994 in words is "eighty-one million, six hundred ninety-four thousand, nine hundred ninety-four".