20994725 has 12 divisors (see below), whose sum is σ = 26738244. Its totient is φ = 16341120.

The previous prime is 20994713. The next prime is 20994749. The reversal of 20994725 is 52749902.

It is a Cunningham number, because it is equal to 4582²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 1643524 + 19351201 = 1282^2 + 4399^2 .

It is not a de Polignac number, because 20994725 - 2⁴ = 20994709 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10424 + ... + 12273.

It is an arithmetic number, because the mean of its divisors is an integer number (2228187).

Almost surely, 2^20994725 is an apocalyptic number.

20994725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20994725 is a deficient number, since it is larger than the sum of its proper divisors (5743519).

20994725 is a wasteful number, since it uses less digits than its factorization.

20994725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22744 (or 22739 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 20994725 is about 4582.0001091227. Note that the first 3 decimals coincide. The cubic root of 20994725 is about 275.8693151877.

The spelling of 20994725 in words is "twenty million, nine hundred ninety-four thousand, seven hundred twenty-five".