129766440 has 64 divisors (see below), whose sum is σ = 412205760. Its totient is φ = 32568320.

The previous prime is 129766421. The next prime is 129766489. The reversal of 129766440 is 44667921.

It is a happy number.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29766 + ... + 33845.

It is an arithmetic number, because the mean of its divisors is an integer number (6440715).

Almost surely, 2^129766440 is an apocalyptic number.

129766440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129766440 is an abundant number, since it is smaller than the sum of its proper divisors (282439320).

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

129766440 is a wasteful number, since it uses less digits than its factorization.

129766440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63642 (or 63638 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 129766440 is about 11391.5073629437. The cubic root of 129766440 is about 506.2761437497.

The spelling of 129766440 in words is "one hundred twenty-nine million, seven hundred sixty-six thousand, four hundred forty".