81938959 has 8 divisors (see below), whose sum is σ = 82682240. Its totient is φ = 81198936.

The previous prime is 81938957. The next prime is 81938981. The reversal of 81938959 is 95983918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81938959 - 2¹ = 81938957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81938953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88702 + ... + 89620.

It is an arithmetic number, because the mean of its divisors is an integer number (10335280).

Almost surely, 2^81938959 is an apocalyptic number.

81938959 is a deficient number, since it is larger than the sum of its proper divisors (743281).

81938959 is a wasteful number, since it uses less digits than its factorization.

81938959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1629.

The product of its digits is 699840, while the sum is 52.

The square root of 81938959 is about 9052.0140852741. The cubic root of 81938959 is about 434.3403203961.

The spelling of 81938959 in words is "eighty-one million, nine hundred thirty-eight thousand, nine hundred fifty-nine".