20052509 has 4 divisors (see below), whose sum is σ = 20070204. Its totient is φ = 20034816.

The previous prime is 20052479. The next prime is 20052521. The reversal of 20052509 is 90525002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6708100 + 13344409 = 2590^2 + 3653^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20052509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20052559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7022 + ... + 9455.

It is an arithmetic number, because the mean of its divisors is an integer number (5017551).

Almost surely, 2^20052509 is an apocalyptic number.

It is an amenable number.

20052509 is a deficient number, since it is larger than the sum of its proper divisors (17695).

20052509 is a wasteful number, since it uses less digits than its factorization.

20052509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17694.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 20052509 is about 4478.0027914239. The cubic root of 20052509 is about 271.6791063260.

The spelling of 20052509 in words is "twenty million, fifty-two thousand, five hundred nine".