129312649 has 2 divisors, whose sum is σ = 129312650. Its totient is φ = 129312648.

The previous prime is 129312611. The next prime is 129312661. The reversal of 129312649 is 946213921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129231424 + 81225 = 11368^2 + 285^2 .

It is a cyclic number.

It is not a de Polignac number, because 129312649 - 2¹³ = 129304457 is a prime.

It is a super-2 number, since 2×129312649² = 33443522382794402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129312679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64656324 + 64656325.

It is an arithmetic number, because the mean of its divisors is an integer number (64656325).

Almost surely, 2^129312649 is an apocalyptic number.

It is an amenable number.

129312649 is a deficient number, since it is larger than the sum of its proper divisors (1).

129312649 is an equidigital number, since it uses as much as digits as its factorization.

129312649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 37.

The square root of 129312649 is about 11371.5719669710. The cubic root of 129312649 is about 505.6853081887.

The spelling of 129312649 in words is "one hundred twenty-nine million, three hundred twelve thousand, six hundred forty-nine".