2565530644 has 6 divisors (see below), whose sum is σ = 4489678634. Its totient is φ = 1282765320.

The previous prime is 2565530641. The next prime is 2565530647. The reversal of 2565530644 is 4460355652.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2565530641) and next prime (2565530647).

It can be written as a sum of positive squares in only one way, i.e., 1988089744 + 577440900 = 44588^2 + 24030^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2565530597 and 2565530606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565530641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320691327 + ... + 320691334.

Almost surely, 2^2565530644 is an apocalyptic number.

It is an amenable number.

2565530644 is a deficient number, since it is larger than the sum of its proper divisors (1924147990).

2565530644 is a wasteful number, since it uses less digits than its factorization.

2565530644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641382665 (or 641382663 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 40.

The square root of 2565530644 is about 50651.0675504475. The cubic root of 2565530644 is about 1368.9651808677.

The spelling of 2565530644 in words is "two billion, five hundred sixty-five million, five hundred thirty thousand, six hundred forty-four".