129623040 has 264 divisors, whose sum is σ = 469418040. Its totient is φ = 33030144.

The previous prime is 129623033. The next prime is 129623047. The reversal of 129623040 is 40326921.

It is an interprime number because it is at equal distance from previous prime (129623033) and next prime (129623047).

It can be written as a sum of positive squares in 4 ways, for example, as 11943936 + 117679104 = 3456^2 + 10848^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129622995 and 129623013.

It is not an unprimeable number, because it can be changed into a prime (129623047) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1336272 + ... + 1336368.

Almost surely, 2^129623040 is an apocalyptic number.

129623040 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 129623040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234709020).

129623040 is an abundant number, since it is smaller than the sum of its proper divisors (339795000).

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

129623040 is a wasteful number, since it uses less digits than its factorization.

129623040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 129623040 is about 11385.2114604868. The cubic root of 129623040 is about 506.0895861211.

Adding to 129623040 its reverse (40326921), we get a palindrome (169949961).

It can be divided in two parts, 1296 and 23040, that added together give a square (24336 = 156²).

The spelling of 129623040 in words is "one hundred twenty-nine million, six hundred twenty-three thousand, forty".