129227921 has 2 divisors, whose sum is σ = 129227922. Its totient is φ = 129227920.

The previous prime is 129227909. The next prime is 129227927. The reversal of 129227921 is 129722921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114490000 + 14737921 = 10700^2 + 3839^2 .

It is a cyclic number.

It is not a de Polignac number, because 129227921 - 2¹⁰ = 129226897 is a prime.

It is not a weakly prime, because it can be changed into another prime (129227927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64613960 + 64613961.

It is an arithmetic number, because the mean of its divisors is an integer number (64613961).

Almost surely, 2^129227921 is an apocalyptic number.

It is an amenable number.

129227921 is a deficient number, since it is larger than the sum of its proper divisors (1).

129227921 is an equidigital number, since it uses as much as digits as its factorization.

129227921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 35.

The square root of 129227921 is about 11367.8459261199. The cubic root of 129227921 is about 505.5748393204.

The spelling of 129227921 in words is "one hundred twenty-nine million, two hundred twenty-seven thousand, nine hundred twenty-one".