2566500644 has 6 divisors (see below), whose sum is σ = 4491376134. Its totient is φ = 1283250320.

The previous prime is 2566500637. The next prime is 2566500647. The reversal of 2566500644 is 4460056652.

It can be written as a sum of positive squares in only one way, i.e., 2486219044 + 80281600 = 49862^2 + 8960^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2566500598 and 2566500607.

It is not an unprimeable number, because it can be changed into a prime (2566500647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320812577 + ... + 320812584.

It is an arithmetic number, because the mean of its divisors is an integer number (748562689).

Almost surely, 2^2566500644 is an apocalyptic number.

It is an amenable number.

2566500644 is a deficient number, since it is larger than the sum of its proper divisors (1924875490).

2566500644 is a wasteful number, since it uses less digits than its factorization.

2566500644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641625165 (or 641625163 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 38.

The square root of 2566500644 is about 50660.6419619807. The cubic root of 2566500644 is about 1369.1376895466.

The spelling of 2566500644 in words is "two billion, five hundred sixty-six million, five hundred thousand, six hundred forty-four".