129421723 has 2 divisors, whose sum is σ = 129421724. Its totient is φ = 129421722.

The previous prime is 129421639. The next prime is 129421739. The reversal of 129421723 is 327124921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129421723 - 2⁹ = 129421211 is a prime.

It is not a weakly prime, because it can be changed into another prime (129421783) 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, 64710861 + 64710862.

It is an arithmetic number, because the mean of its divisors is an integer number (64710862).

Almost surely, 2^129421723 is an apocalyptic number.

129421723 is a deficient number, since it is larger than the sum of its proper divisors (1).

129421723 is an equidigital number, since it uses as much as digits as its factorization.

129421723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 31.

The square root of 129421723 is about 11376.3668629312. The cubic root of 129421723 is about 505.8274484944.

The spelling of 129421723 in words is "one hundred twenty-nine million, four hundred twenty-one thousand, seven hundred twenty-three".