81429379 has 2 divisors, whose sum is σ = 81429380. Its totient is φ = 81429378.

The previous prime is 81429373. The next prime is 81429409. The reversal of 81429379 is 97392418.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81429379 - 2⁵ = 81429347 is a prime.

It is not a weakly prime, because it can be changed into another prime (81429373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40714689 + 40714690.

It is an arithmetic number, because the mean of its divisors is an integer number (40714690).

Almost surely, 2^81429379 is an apocalyptic number.

81429379 is a deficient number, since it is larger than the sum of its proper divisors (1).

81429379 is an equidigital number, since it uses as much as digits as its factorization.

81429379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 43.

The square root of 81429379 is about 9023.8228595202. The cubic root of 81429379 is about 433.4380570694.

The spelling of 81429379 in words is "eighty-one million, four hundred twenty-nine thousand, three hundred seventy-nine".