2643974656 has 20 divisors (see below), whose sum is σ = 5282786322. Its totient is φ = 1321987072.

The previous prime is 2643974639. The next prime is 2643974681. The reversal of 2643974656 is 6564793462.

It can be written as a sum of positive squares in only one way, i.e., 2302464256 + 341510400 = 47984^2 + 18480^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2581495 + ... + 2582518.

Almost surely, 2^2643974656 is an apocalyptic number.

It is an amenable number.

2643974656 is a deficient number, since it is larger than the sum of its proper divisors (2638811666).

2643974656 is an frugal number, since it uses more digits than its factorization.

2643974656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5164031 (or 5164015 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 52.

The square root of 2643974656 is about 51419.5940863014. The cubic root of 2643974656 is about 1382.7778980873. Note that the first 3 decimals are identical.

The spelling of 2643974656 in words is "two billion, six hundred forty-three million, nine hundred seventy-four thousand, six hundred fifty-six".