81455929 has 2 divisors, whose sum is σ = 81455930. Its totient is φ = 81455928.

The previous prime is 81455911. The next prime is 81455947. The reversal of 81455929 is 92955418.

It is a balanced prime because it is at equal distance from previous prime (81455911) and next prime (81455947).

It can be written as a sum of positive squares in only one way, i.e., 41576704 + 39879225 = 6448^2 + 6315^2 .

It is a cyclic number.

It is not a de Polignac number, because 81455929 - 2⁹ = 81455417 is a prime.

It is not a weakly prime, because it can be changed into another prime (81455989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40727964 + 40727965.

It is an arithmetic number, because the mean of its divisors is an integer number (40727965).

Almost surely, 2^81455929 is an apocalyptic number.

It is an amenable number.

81455929 is a deficient number, since it is larger than the sum of its proper divisors (1).

81455929 is an equidigital number, since it uses as much as digits as its factorization.

81455929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 43.

The square root of 81455929 is about 9025.2938456318. The cubic root of 81455929 is about 433.4851593564.

The spelling of 81455929 in words is "eighty-one million, four hundred fifty-five thousand, nine hundred twenty-nine".