2565721436 has 24 divisors (see below), whose sum is σ = 4569067440. Its totient is φ = 1260301952.

The previous prime is 2565721397. The next prime is 2565721439. The reversal of 2565721436 is 6341275652.

It is a junction number, because it is equal to n+sod(n) for n = 2565721393 and 2565721402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565721439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 539726 + ... + 544458.

It is an arithmetic number, because the mean of its divisors is an integer number (190377810).

Almost surely, 2^2565721436 is an apocalyptic number.

It is an amenable number.

2565721436 is a deficient number, since it is larger than the sum of its proper divisors (2003346004).

2565721436 is a wasteful number, since it uses less digits than its factorization.

2565721436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7093 (or 7091 counting only the distinct ones).

The product of its digits is 302400, while the sum is 41.

The square root of 2565721436 is about 50652.9509110772. The cubic root of 2565721436 is about 1368.9991155148. Note that the first 3 decimals are identical.

The spelling of 2565721436 in words is "two billion, five hundred sixty-five million, seven hundred twenty-one thousand, four hundred thirty-six".