81698980 has 24 divisors (see below), whose sum is σ = 187165440. Its totient is φ = 29708640.

The previous prime is 81698959. The next prime is 81698999. The reversal of 81698980 is 8989618.

It is a happy number.

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, 185460 + ... + 185899.

It is an arithmetic number, because the mean of its divisors is an integer number (7798560).

Almost surely, 2^81698980 is an apocalyptic number.

It is an amenable number.

81698980 is an abundant number, since it is smaller than the sum of its proper divisors (105466460).

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

81698980 is a wasteful number, since it uses less digits than its factorization.

81698980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371379 (or 371377 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 49.

The square root of 81698980 is about 9038.7488072188. The cubic root of 81698980 is about 433.9158805445.

The spelling of 81698980 in words is "eighty-one million, six hundred ninety-eight thousand, nine hundred eighty".