20129040 has 80 divisors (see below), whose sum is σ = 69340800. Its totient is φ = 5367168.

The previous prime is 20129023. The next prime is 20129047. The reversal of 20129040 is 4092102.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20129047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2500 + ... + 6819.

It is an arithmetic number, because the mean of its divisors is an integer number (866760).

Almost surely, 2^20129040 is an apocalyptic number.

20129040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20129040 is an abundant number, since it is smaller than the sum of its proper divisors (49211760).

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

20129040 is a wasteful number, since it uses less digits than its factorization.

20129040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9341 (or 9329 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20129040 is about 4486.5398694317. The cubic root of 20129040 is about 272.0242913715.

It can be divided in two parts, 201 and 29040, that added together give a square (29241 = 171²).

The spelling of 20129040 in words is "twenty million, one hundred twenty-nine thousand, forty".