81413929 has 2 divisors, whose sum is σ = 81413930. Its totient is φ = 81413928.

The previous prime is 81413909. The next prime is 81413963. The reversal of 81413929 is 92931418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64000000 + 17413929 = 8000^2 + 4173^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81413929 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81413909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40706964 + 40706965.

It is an arithmetic number, because the mean of its divisors is an integer number (40706965).

Almost surely, 2^81413929 is an apocalyptic number.

It is an amenable number.

81413929 is a deficient number, since it is larger than the sum of its proper divisors (1).

81413929 is an equidigital number, since it uses as much as digits as its factorization.

81413929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 37.

The square root of 81413929 is about 9022.9667515735. The cubic root of 81413929 is about 433.4106425513.

The spelling of 81413929 in words is "eighty-one million, four hundred thirteen thousand, nine hundred twenty-nine".