129761440 has 48 divisors (see below), whose sum is σ = 307433448. Its totient is φ = 51757056.

The previous prime is 129761419. The next prime is 129761461. The reversal of 129761440 is 44167921.

It is an interprime number because it is at equal distance from previous prime (129761419) and next prime (129761461).

It can be written as a sum of positive squares in 4 ways, for example, as 38291344 + 91470096 = 6188^2 + 9564^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129761396 and 129761405.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68344 + ... + 70216.

Almost surely, 2^129761440 is an apocalyptic number.

129761440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129761440 is an abundant number, since it is smaller than the sum of its proper divisors (177672008).

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

129761440 is a wasteful number, since it uses less digits than its factorization.

129761440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321 (or 2313 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 129761440 is about 11391.2878990920. The cubic root of 129761440 is about 506.2696412641.

The spelling of 129761440 in words is "one hundred twenty-nine million, seven hundred sixty-one thousand, four hundred forty".