2556443642 has 4 divisors (see below), whose sum is σ = 3834665466. Its totient is φ = 1278221820.

The previous prime is 2556443621. The next prime is 2556443653. The reversal of 2556443642 is 2463446552.

2556443642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1684363681 + 872079961 = 41041^2 + 29531^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2556443642.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639110909 + ... + 639110912.

Almost surely, 2^2556443642 is an apocalyptic number.

2556443642 is a deficient number, since it is larger than the sum of its proper divisors (1278221824).

2556443642 is a wasteful number, since it uses less digits than its factorization.

2556443642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278221823.

The product of its digits is 691200, while the sum is 41.

The square root of 2556443642 is about 50561.2860002591. The cubic root of 2556443642 is about 1367.3469964185.

The spelling of 2556443642 in words is "two billion, five hundred fifty-six million, four hundred forty-three thousand, six hundred forty-two".