81726929 has 2 divisors, whose sum is σ = 81726930. Its totient is φ = 81726928.

The previous prime is 81726919. The next prime is 81726941. The reversal of 81726929 is 92962718.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81721600 + 5329 = 9040^2 + 73^2 .

It is a cyclic number.

It is not a de Polignac number, because 81726929 - 2²⁴ = 64949713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81726929.

It is not a weakly prime, because it can be changed into another prime (81726919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40863464 + 40863465.

It is an arithmetic number, because the mean of its divisors is an integer number (40863465).

Almost surely, 2^81726929 is an apocalyptic number.

It is an amenable number.

81726929 is a deficient number, since it is larger than the sum of its proper divisors (1).

81726929 is an equidigital number, since it uses as much as digits as its factorization.

81726929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 44.

The square root of 81726929 is about 9040.2947407703. The cubic root of 81726929 is about 433.9653553861.

The spelling of 81726929 in words is "eighty-one million, seven hundred twenty-six thousand, nine hundred twenty-nine".