816172539 has 32 divisors (see below), whose sum is σ = 1343806464. Its totient is φ = 429079680.

The previous prime is 816172537. The next prime is 816172541. The reversal of 816172539 is 935271618.

It is an interprime number because it is at equal distance from previous prime (816172537) and next prime (816172541).

It is not a de Polignac number, because 816172539 - 2¹ = 816172537 is a prime.

It is a super-2 number, since 2×816172539² = 1332275226835413042, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 816172539.

It is not an unprimeable number, because it can be changed into a prime (816172537) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80097 + ... + 89709.

It is an arithmetic number, because the mean of its divisors is an integer number (41993952).

Almost surely, 2^816172539 is an apocalyptic number.

816172539 is a deficient number, since it is larger than the sum of its proper divisors (527633925).

816172539 is a wasteful number, since it uses less digits than its factorization.

816172539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9947.

The product of its digits is 90720, while the sum is 42.

The square root of 816172539 is about 28568.7335911132. The cubic root of 816172539 is about 934.5316036869.

The spelling of 816172539 in words is "eight hundred sixteen million, one hundred seventy-two thousand, five hundred thirty-nine".