81667794 has 32 divisors (see below), whose sum is σ = 177105600. Its totient is φ = 24956352.

The previous prime is 81667771. The next prime is 81667823. The reversal of 81667794 is 49776618.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8109 + ... + 15135.

It is an arithmetic number, because the mean of its divisors is an integer number (5534550).

Almost surely, 2^81667794 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81667794, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88552800).

81667794 is an abundant number, since it is smaller than the sum of its proper divisors (95437806).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81667794 is a wasteful number, since it uses less digits than its factorization.

81667794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7194.

The product of its digits is 508032, while the sum is 48.

The square root of 81667794 is about 9037.0235144100. The cubic root of 81667794 is about 433.8606622997.

The spelling of 81667794 in words is "eighty-one million, six hundred sixty-seven thousand, seven hundred ninety-four".