81616739 has 2 divisors, whose sum is σ = 81616740. Its totient is φ = 81616738.

The previous prime is 81616727. The next prime is 81616747. The reversal of 81616739 is 93761618.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81616739 is a prime.

It is a super-2 number, since 2×81616739² = 13322584169988242, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 81616696 and 81616705.

It is not a weakly prime, because it can be changed into another prime (81616789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40808369 + 40808370.

It is an arithmetic number, because the mean of its divisors is an integer number (40808370).

Almost surely, 2^81616739 is an apocalyptic number.

81616739 is a deficient number, since it is larger than the sum of its proper divisors (1).

81616739 is an equidigital number, since it uses as much as digits as its factorization.

81616739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 41.

The square root of 81616739 is about 9034.1983042216. The cubic root of 81616739 is about 433.7702334517.

The spelling of 81616739 in words is "eighty-one million, six hundred sixteen thousand, seven hundred thirty-nine".