20729925 has 60 divisors (see below), whose sum is σ = 39835620. Its totient is φ = 10644480.

The previous prime is 20729909. The next prime is 20729927. The reversal of 20729925 is 52992702.

It can be written as a sum of positive squares in 6 ways, for example, as 641601 + 20088324 = 801^2 + 4482^2 .

It is not a de Polignac number, because 20729925 - 2⁴ = 20729909 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20729925.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20729927) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 58549 + ... + 58901.

It is an arithmetic number, because the mean of its divisors is an integer number (663927).

Almost surely, 2^20729925 is an apocalyptic number.

20729925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20729925 is a deficient number, since it is larger than the sum of its proper divisors (19105695).

20729925 is a wasteful number, since it uses less digits than its factorization.

20729925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20729925 is about 4553.0127388357. The cubic root of 20729925 is about 274.7045863523.

The spelling of 20729925 in words is "twenty million, seven hundred twenty-nine thousand, nine hundred twenty-five".