18020725 has 6 divisors (see below), whose sum is σ = 22345730. Its totient is φ = 14416560.

The previous prime is 18020701. The next prime is 18020747. The reversal of 18020725 is 52702081.

It can be written as a sum of positive squares in 3 ways, for example, as 1423249 + 16597476 = 1193^2 + 4074^2 .

It is not a de Polignac number, because 18020725 - 2²¹ = 15923573 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: 720829 = 18020725 / (1 + 8 + 0 + 2 + 0 + 7 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 18020725.

It is a congruent 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, 360390 + ... + 360439.

Almost surely, 2^18020725 is an apocalyptic number.

It is an amenable number.

18020725 is a deficient number, since it is larger than the sum of its proper divisors (4325005).

18020725 is an equidigital number, since it uses as much as digits as its factorization.

18020725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720839 (or 720834 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 18020725 is about 4245.0824491404. The cubic root of 18020725 is about 262.1746839262.

The spelling of 18020725 in words is "eighteen million, twenty thousand, seven hundred twenty-five".