81699192 has 40 divisors (see below), whose sum is σ = 228835200. Its totient is φ = 27232848.

The previous prime is 81699187. The next prime is 81699199. The reversal of 81699192 is 29199618.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81699199) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 62392 + ... + 63687.

It is an arithmetic number, because the mean of its divisors is an integer number (5720880).

Almost surely, 2^81699192 is an apocalyptic number.

It is an amenable number.

81699192 is an abundant number, since it is smaller than the sum of its proper divisors (147136008).

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

81699192 is a wasteful number, since it uses less digits than its factorization.

81699192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126097 (or 126084 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 81699192 is about 9038.7605344981. The cubic root of 81699192 is about 433.9162558658.

The spelling of 81699192 in words is "eighty-one million, six hundred ninety-nine thousand, one hundred ninety-two".