129311640 has 160 divisors (see below), whose sum is σ = 439868880. Its totient is φ = 34069248.

The previous prime is 129311629. The next prime is 129311641. The reversal of 129311640 is 46113921.

129311640 = T₁₇₅ + T₁₇₆ + ... + T₉₂₀.

129311640 is a `hidden beast` number, since 1 + 2 + 9 + 3 + 11 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129311641) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 346494 + ... + 346866.

Almost surely, 2^129311640 is an apocalyptic number.

129311640 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 129311640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219934440).

129311640 is an abundant number, since it is smaller than the sum of its proper divisors (310557240).

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

129311640 is a wasteful number, since it uses less digits than its factorization.

129311640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 129311640 is about 11371.5276018660. The cubic root of 129311640 is about 505.6839929325.

The spelling of 129311640 in words is "one hundred twenty-nine million, three hundred eleven thousand, six hundred forty".