81946774 has 16 divisors (see below), whose sum is σ = 151286688. Its totient is φ = 32418432.

The previous prime is 81946771. The next prime is 81946789. The reversal of 81946774 is 47764918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81946771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224947 + ... + 225310.

It is an arithmetic number, because the mean of its divisors is an integer number (9455418).

Almost surely, 2^81946774 is an apocalyptic number.

81946774 is a deficient number, since it is larger than the sum of its proper divisors (69339914).

81946774 is a wasteful number, since it uses less digits than its factorization.

81946774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450279.

The product of its digits is 338688, while the sum is 46.

The square root of 81946774 is about 9052.4457468686. The cubic root of 81946774 is about 434.3541284867.

The spelling of 81946774 in words is "eighty-one million, nine hundred forty-six thousand, seven hundred seventy-four".