81894633 has 8 divisors (see below), whose sum is σ = 111516288. Its totient is φ = 53434704.

The previous prime is 81894611. The next prime is 81894641. The reversal of 81894633 is 33649818.

It is a happy number.

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

It is not a de Polignac number, because 81894633 - 2⁹ = 81894121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81894233) 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, 290266 + ... + 290547.

It is an arithmetic number, because the mean of its divisors is an integer number (13939536).

Almost surely, 2^81894633 is an apocalyptic number.

It is an amenable number.

81894633 is a deficient number, since it is larger than the sum of its proper divisors (29621655).

81894633 is a wasteful number, since it uses less digits than its factorization.

81894633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580863.

The product of its digits is 124416, while the sum is 42.

The square root of 81894633 is about 9049.5653486784. The cubic root of 81894633 is about 434.2619854910.

The spelling of 81894633 in words is "eighty-one million, eight hundred ninety-four thousand, six hundred thirty-three".