129969840 has 320 divisors, whose sum is σ = 541965312. Its totient is φ = 24883200.

The previous prime is 129969839. The next prime is 129969841. The reversal of 129969840 is 48969921.

It is an interprime number because it is at equal distance from previous prime (129969839) and next prime (129969841).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 129969840.

It is not an unprimeable number, because it can be changed into a prime (129969841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 239970 + ... + 240510.

Almost surely, 2^129969840 is an apocalyptic number.

129969840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129969840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270982656).

129969840 is an abundant number, since it is smaller than the sum of its proper divisors (411995472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129969840 is a wasteful number, since it uses less digits than its factorization.

129969840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 48.

The square root of 129969840 is about 11400.4315707784. The cubic root of 129969840 is about 506.5405233832.

It can be divided in two parts, 129 and 969840, that added together give a palindrome (969969).

The spelling of 129969840 in words is "one hundred twenty-nine million, nine hundred sixty-nine thousand, eight hundred forty".