129911261 has 2 divisors, whose sum is σ = 129911262. Its totient is φ = 129911260.

The previous prime is 129911233. The next prime is 129911269. The reversal of 129911261 is 162119921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65108761 + 64802500 = 8069^2 + 8050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129911261 is a prime.

It is a super-2 number, since 2×129911261² = 33753871469220242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129911269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64955630 + 64955631.

It is an arithmetic number, because the mean of its divisors is an integer number (64955631).

Almost surely, 2^129911261 is an apocalyptic number.

It is an amenable number.

129911261 is a deficient number, since it is larger than the sum of its proper divisors (1).

129911261 is an equidigital number, since it uses as much as digits as its factorization.

129911261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 32.

The square root of 129911261 is about 11397.8621241003. The cubic root of 129911261 is about 506.4644106061.

The spelling of 129911261 in words is "one hundred twenty-nine million, nine hundred eleven thousand, two hundred sixty-one".