129649665 has 32 divisors (see below), whose sum is σ = 215815680. Its totient is φ = 66403584.

The previous prime is 129649649. The next prime is 129649669. The reversal of 129649665 is 566946921.

It is not a de Polignac number, because 129649665 - 2⁴ = 129649649 is a prime.

It is a super-2 number, since 2×129649665² = 33618071269224450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129649669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42367 + ... + 45323.

It is an arithmetic number, because the mean of its divisors is an integer number (6744240).

Almost surely, 2^129649665 is an apocalyptic number.

129649665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129649665 is a deficient number, since it is larger than the sum of its proper divisors (86166015).

129649665 is a wasteful number, since it uses less digits than its factorization.

129649665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3081.

The product of its digits is 699840, while the sum is 48.

The square root of 129649665 is about 11386.3806804445. The cubic root of 129649665 is about 506.1242345724.

The spelling of 129649665 in words is "one hundred twenty-nine million, six hundred forty-nine thousand, six hundred sixty-five".