81630680 has 32 divisors (see below), whose sum is σ = 191656800. Its totient is φ = 31232256.

The previous prime is 81630667. The next prime is 81630683. The reversal of 81630680 is 8603618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81630683) 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, 43445 + ... + 45284.

It is an arithmetic number, because the mean of its divisors is an integer number (5989275).

Almost surely, 2^81630680 is an apocalyptic number.

It is an amenable number.

81630680 is an abundant number, since it is smaller than the sum of its proper divisors (110026120).

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

81630680 is a wasteful number, since it uses less digits than its factorization.

81630680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88763 (or 88759 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 81630680 is about 9034.9698394627. The cubic root of 81630680 is about 433.7949295562.

The spelling of 81630680 in words is "eighty-one million, six hundred thirty thousand, six hundred eighty".