81602939 has 4 divisors (see below), whose sum is σ = 89021400. Its totient is φ = 74184480.

The previous prime is 81602923. The next prime is 81602957. The reversal of 81602939 is 93920618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81602939 - 2⁴ = 81602923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81602039) 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, 3709214 + ... + 3709235.

It is an arithmetic number, because the mean of its divisors is an integer number (22255350).

Almost surely, 2^81602939 is an apocalyptic number.

81602939 is a deficient number, since it is larger than the sum of its proper divisors (7418461).

81602939 is a wasteful number, since it uses less digits than its factorization.

81602939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7418460.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 81602939 is about 9033.4345074285. The cubic root of 81602939 is about 433.7457843550.

The spelling of 81602939 in words is "eighty-one million, six hundred two thousand, nine hundred thirty-nine".