20825989 has 2 divisors, whose sum is σ = 20825990. Its totient is φ = 20825988.

The previous prime is 20825983. The next prime is 20825993. The reversal of 20825989 is 98952802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20775364 + 50625 = 4558^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 20825989 - 2¹⁵ = 20793221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20825983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10412994 + 10412995.

It is an arithmetic number, because the mean of its divisors is an integer number (10412995).

Almost surely, 2^20825989 is an apocalyptic number.

It is an amenable number.

20825989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20825989 is an equidigital number, since it uses as much as digits as its factorization.

20825989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 20825989 is about 4563.5500435516. The cubic root of 20825989 is about 275.1282663351.

The spelling of 20825989 in words is "twenty million, eight hundred twenty-five thousand, nine hundred eighty-nine".