20625569 has 2 divisors, whose sum is σ = 20625570. Its totient is φ = 20625568.

The previous prime is 20625547. The next prime is 20625581. The reversal of 20625569 is 96552602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12285025 + 8340544 = 3505^2 + 2888^2 .

It is a cyclic number.

It is not a de Polignac number, because 20625569 - 2⁸ = 20625313 is a prime.

It is a super-2 number, since 2×20625569² = 850828193147522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20625529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10312784 + 10312785.

It is an arithmetic number, because the mean of its divisors is an integer number (10312785).

Almost surely, 2^20625569 is an apocalyptic number.

It is an amenable number.

20625569 is a deficient number, since it is larger than the sum of its proper divisors (1).

20625569 is an equidigital number, since it uses as much as digits as its factorization.

20625569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 20625569 is about 4541.5381755524. The cubic root of 20625569 is about 274.2428495014.

The spelling of 20625569 in words is "twenty million, six hundred twenty-five thousand, five hundred sixty-nine".