81716039 has 4 divisors (see below), whose sum is σ = 83616456. Its totient is φ = 79815624.

The previous prime is 81716009. The next prime is 81716053. The reversal of 81716039 is 93061718.

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 81716039 - 2¹² = 81711943 is a prime.

It is a super-2 number, since 2×81716039² = 13355022059699042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81716009) 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, 950144 + ... + 950229.

It is an arithmetic number, because the mean of its divisors is an integer number (20904114).

Almost surely, 2^81716039 is an apocalyptic number.

81716039 is a deficient number, since it is larger than the sum of its proper divisors (1900417).

81716039 is a wasteful number, since it uses less digits than its factorization.

81716039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900416.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 81716039 is about 9039.6924173337. The cubic root of 81716039 is about 433.9460794359.

The spelling of 81716039 in words is "eighty-one million, seven hundred sixteen thousand, thirty-nine".