81698180272 has 20 divisors (see below), whose sum is σ = 158553621016. Its totient is φ = 40781116800.

The previous prime is 81698180269. The next prime is 81698180273. The reversal of 81698180272 is 27208189618.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81698180273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4238418 + ... + 4257649.

Almost surely, 2^81698180272 is an apocalyptic number.

It is an amenable number.

81698180272 is a deficient number, since it is larger than the sum of its proper divisors (76855440744).

81698180272 is a wasteful number, since it uses less digits than its factorization.

81698180272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8496676 (or 8496670 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 52.

The spelling of 81698180272 in words is "eighty-one billion, six hundred ninety-eight million, one hundred eighty thousand, two hundred seventy-two".