81642292 has 12 divisors (see below), whose sum is σ = 143730720. Its totient is φ = 40576376.

The previous prime is 81642287. The next prime is 81642293. The reversal of 81642292 is 29224618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81642293) 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, 60442 + ... + 61777.

It is an arithmetic number, because the mean of its divisors is an integer number (11977560).

Almost surely, 2^81642292 is an apocalyptic number.

It is an amenable number.

81642292 is a deficient number, since it is larger than the sum of its proper divisors (62088428).

81642292 is a wasteful number, since it uses less digits than its factorization.

81642292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122390 (or 122388 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 81642292 is about 9035.6124308206. The cubic root of 81642292 is about 433.8154977539.

The spelling of 81642292 in words is "eighty-one million, six hundred forty-two thousand, two hundred ninety-two".