81633018 has 16 divisors (see below), whose sum is σ = 164123136. Its totient is φ = 27068160.

The previous prime is 81633007. The next prime is 81633037. The reversal of 81633018 is 81033618.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34471 + ... + 36762.

It is an arithmetic number, because the mean of its divisors is an integer number (10257696).

Almost surely, 2^81633018 is an apocalyptic number.

81633018 is an abundant number, since it is smaller than the sum of its proper divisors (82490118).

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

81633018 is a wasteful number, since it uses less digits than its factorization.

81633018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71429.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 81633018 is about 9035.0992246903. The cubic root of 81633018 is about 433.7990709847.

The spelling of 81633018 in words is "eighty-one million, six hundred thirty-three thousand, eighteen".