129319621 has 2 divisors, whose sum is σ = 129319622. Its totient is φ = 129319620.

The previous prime is 129319609. The next prime is 129319649. The reversal of 129319621 is 126913921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96314596 + 33005025 = 9814^2 + 5745^2 .

It is a cyclic number.

It is not a de Polignac number, because 129319621 - 2⁹ = 129319109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129319601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64659810 + 64659811.

It is an arithmetic number, because the mean of its divisors is an integer number (64659811).

Almost surely, 2^129319621 is an apocalyptic number.

It is an amenable number.

129319621 is a deficient number, since it is larger than the sum of its proper divisors (1).

129319621 is an equidigital number, since it uses as much as digits as its factorization.

129319621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 129319621 is about 11371.8785167623. The cubic root of 129319621 is about 505.6943961746.

The spelling of 129319621 in words is "one hundred twenty-nine million, three hundred nineteen thousand, six hundred twenty-one".