81942201 has 12 divisors (see below), whose sum is σ = 129121200. Its totient is φ = 49661880.

The previous prime is 81942199. The next prime is 81942229. The reversal of 81942201 is 10224918.

It is not a de Polignac number, because 81942201 - 2¹ = 81942199 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81942251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 413751 + ... + 413948.

It is an arithmetic number, because the mean of its divisors is an integer number (10760100).

Almost surely, 2^81942201 is an apocalyptic number.

It is an amenable number.

81942201 is a deficient number, since it is larger than the sum of its proper divisors (47178999).

81942201 is a wasteful number, since it uses less digits than its factorization.

81942201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827716 (or 827713 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 81942201 is about 9052.1931596713. The cubic root of 81942201 is about 434.3460486958.

The spelling of 81942201 in words is "eighty-one million, nine hundred forty-two thousand, two hundred one".