129289421 has 2 divisors, whose sum is σ = 129289422. Its totient is φ = 129289420.

The previous prime is 129289409. The next prime is 129289483. The reversal of 129289421 is 124982921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89775625 + 39513796 = 9475^2 + 6286^2 .

It is a cyclic number.

It is not a de Polignac number, because 129289421 - 2²⁶ = 62180557 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129289021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64644710 + 64644711.

It is an arithmetic number, because the mean of its divisors is an integer number (64644711).

Almost surely, 2^129289421 is an apocalyptic number.

It is an amenable number.

129289421 is a deficient number, since it is larger than the sum of its proper divisors (1).

129289421 is an equidigital number, since it uses as much as digits as its factorization.

129289421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 129289421 is about 11370.5506023235. The cubic root of 129289421 is about 505.6550281870.

The spelling of 129289421 in words is "one hundred twenty-nine million, two hundred eighty-nine thousand, four hundred twenty-one".