129609649 has 24 divisors (see below), whose sum is σ = 150008760. Its totient is φ = 111541248.

The previous prime is 129609643. The next prime is 129609653. The reversal of 129609649 is 946906921.

It can be written as a sum of positive squares in 12 ways, for example, as 378225 + 129231424 = 615^2 + 11368^2 .

It is not a de Polignac number, because 129609649 - 2⁷ = 129609521 is a prime.

It is a super-2 number, since 2×129609649² = 33597322227806402, which contains 22 as substring.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129609599 and 129609608.

It is not an unprimeable number, because it can be changed into a prime (129609643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 565867 + ... + 566095.

It is an arithmetic number, because the mean of its divisors is an integer number (6250365).

Almost surely, 2^129609649 is an apocalyptic number.

It is an amenable number.

129609649 is a deficient number, since it is larger than the sum of its proper divisors (20399111).

129609649 is a wasteful number, since it uses less digits than its factorization.

129609649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 129609649 is about 11384.6233578454. The cubic root of 129609649 is about 506.0721579462.

The spelling of 129609649 in words is "one hundred twenty-nine million, six hundred nine thousand, six hundred forty-nine".