2569681 has 2 divisors, whose sum is σ = 2569682. Its totient is φ = 2569680.

The previous prime is 2569667. The next prime is 2569691. The reversal of 2569681 is 1869652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1587600 + 982081 = 1260^2 + 991^2 .

It is a cyclic number.

It is not a de Polignac number, because 2569681 - 2⁵ = 2569649 is a prime.

It is a super-2 number, since 2×2569681² = 13206520883522, which contains 22 as substring.

2569681 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2569681.

It is not a weakly prime, because it can be changed into another prime (2569691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1284840 + 1284841.

It is an arithmetic number, because the mean of its divisors is an integer number (1284841).

2^2569681 is an apocalyptic number.

It is an amenable number.

2569681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2569681 is an equidigital number, since it uses as much as digits as its factorization.

2569681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 37.

The square root of 2569681 is about 1603.0224577341. The cubic root of 2569681 is about 136.9702992073.

The spelling of 2569681 in words is "two million, five hundred sixty-nine thousand, six hundred eighty-one".