20709025 has 6 divisors (see below), whose sum is σ = 25679222. Its totient is φ = 16567200.

The previous prime is 20708971. The next prime is 20709041. The reversal of 20709025 is 52090702.

It can be written as a sum of positive squares in 3 ways, for example, as 215296 + 20493729 = 464^2 + 4527^2 .

It is not a de Polignac number, because 20709025 - 2¹³ = 20700833 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 828361 = 20709025 / (2 + 0 + 7 + 0 + 9 + 0 + 2 + 5).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 414156 + ... + 414205.

Almost surely, 2^20709025 is an apocalyptic number.

20709025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20709025 is a deficient number, since it is larger than the sum of its proper divisors (4970197).

20709025 is an equidigital number, since it uses as much as digits as its factorization.

20709025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828371 (or 828366 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 20709025 is about 4550.7169764774. The cubic root of 20709025 is about 274.6122358588.

Adding to 20709025 its reverse (52090702), we get a palindrome (72799727).

The spelling of 20709025 in words is "twenty million, seven hundred nine thousand, twenty-five".