129826640 has 20 divisors (see below), whose sum is σ = 301847124. Its totient is φ = 51930624.

The previous prime is 129826583. The next prime is 129826679. The reversal of 129826640 is 46628921.

It can be written as a sum of positive squares in 2 ways, for example, as 99840064 + 29986576 = 9992^2 + 5476^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 129826594 and 129826603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 811337 + ... + 811496.

Almost surely, 2^129826640 is an apocalyptic number.

129826640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129826640 is an abundant number, since it is smaller than the sum of its proper divisors (172020484).

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

129826640 is a wasteful number, since it uses less digits than its factorization.

129826640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622846 (or 1622840 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 129826640 is about 11394.1493758859. The cubic root of 129826640 is about 506.3544205678.

The spelling of 129826640 in words is "one hundred twenty-nine million, eight hundred twenty-six thousand, six hundred forty".