129737921 has 2 divisors, whose sum is σ = 129737922. Its totient is φ = 129737920.

The previous prime is 129737891. The next prime is 129737939.

129737921 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84364225 + 45373696 = 9185^2 + 6736^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 129737921 - 2¹⁸ = 129475777 is a prime.

It is not a weakly prime, because it can be changed into another prime (129737521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64868960 + 64868961.

It is an arithmetic number, because the mean of its divisors is an integer number (64868961).

Almost surely, 2^129737921 is an apocalyptic number.

It is an amenable number.

129737921 is a deficient number, since it is larger than the sum of its proper divisors (1).

129737921 is an equidigital number, since it uses as much as digits as its factorization.

129737921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47628, while the sum is 41.

The square root of 129737921 is about 11390.2555283014. The cubic root of 129737921 is about 506.2390526312.

The spelling of 129737921 in words is "one hundred twenty-nine million, seven hundred thirty-seven thousand, nine hundred twenty-one".