81986630 has 32 divisors (see below), whose sum is σ = 166192128. Its totient is φ = 28850400.

The previous prime is 81986629. The next prime is 81986647. The reversal of 81986630 is 3668918.

It is a happy number.

It is a Curzon number.

It is a congruent number.

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, 8612 + ... + 15431.

It is an arithmetic number, because the mean of its divisors is an integer number (5193504).

Almost surely, 2^81986630 is an apocalyptic number.

81986630 is an abundant number, since it is smaller than the sum of its proper divisors (84205498).

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

81986630 is a wasteful number, since it uses less digits than its factorization.

81986630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24092.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 81986630 is about 9054.6468732911. The cubic root of 81986630 is about 434.4245352132.

The spelling of 81986630 in words is "eighty-one million, nine hundred eighty-six thousand, six hundred thirty".