129974561 has 2 divisors, whose sum is σ = 129974562. Its totient is φ = 129974560.

The previous prime is 129974557. The next prime is 129974563. The reversal of 129974561 is 165479921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128686336 + 1288225 = 11344^2 + 1135^2 .

It is a cyclic number.

It is not a de Polignac number, because 129974561 - 2² = 129974557 is a prime.

Together with 129974563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129974563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64987280 + 64987281.

It is an arithmetic number, because the mean of its divisors is an integer number (64987281).

Almost surely, 2^129974561 is an apocalyptic number.

It is an amenable number.

129974561 is a deficient number, since it is larger than the sum of its proper divisors (1).

129974561 is an equidigital number, since it uses as much as digits as its factorization.

129974561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 44.

The square root of 129974561 is about 11400.6386224632. The cubic root of 129974561 is about 506.5466564698.

The spelling of 129974561 in words is "one hundred twenty-nine million, nine hundred seventy-four thousand, five hundred sixty-one".