20500129 has 8 divisors (see below), whose sum is σ = 22838760. Its totient is φ = 18270336.

The previous prime is 20500097. The next prime is 20500159. The reversal of 20500129 is 92100502.

It can be written as a sum of positive squares in 4 ways, for example, as 3294225 + 17205904 = 1815^2 + 4148^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20500129 - 2⁵ = 20500097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20500159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26812 + ... + 27565.

It is an arithmetic number, because the mean of its divisors is an integer number (2854845).

Almost surely, 2^20500129 is an apocalyptic number.

20500129 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20500129 is a deficient number, since it is larger than the sum of its proper divisors (2338631).

20500129 is a wasteful number, since it uses less digits than its factorization.

20500129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54419.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20500129 is about 4527.7068147132. The cubic root of 20500129 is about 273.6857578101.

The spelling of 20500129 in words is "twenty million, five hundred thousand, one hundred twenty-nine".