20825729 has 6 divisors (see below), whose sum is σ = 21979890. Its totient is φ = 19729296.

The previous prime is 20825723. The next prime is 20825737. The reversal of 20825729 is 92752802.

It can be written as a sum of positive squares in only one way, i.e., 14440000 + 6385729 = 3800^2 + 2527^2 .

It is not a de Polignac number, because 20825729 - 2⁴ = 20825713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20825723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28484 + ... + 29205.

It is an arithmetic number, because the mean of its divisors is an integer number (3663315).

Almost surely, 2^20825729 is an apocalyptic number.

It is an amenable number.

20825729 is a deficient number, since it is larger than the sum of its proper divisors (1154161).

20825729 is an equidigital number, since it uses as much as digits as its factorization.

20825729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57727 (or 57708 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 20825729 is about 4563.5215568681. The cubic root of 20825729 is about 275.1271213931.

The spelling of 20825729 in words is "twenty million, eight hundred twenty-five thousand, seven hundred twenty-nine".