1643036644 has 12 divisors (see below), whose sum is σ = 2974463100. Its totient is φ = 793190048.

The previous prime is 1643036617. The next prime is 1643036651. The reversal of 1643036644 is 4466303461.

It can be written as a sum of positive squares in 2 ways, for example, as 571783744 + 1071252900 = 23912^2 + 32730^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7081939 + ... + 7082170.

It is an arithmetic number, because the mean of its divisors is an integer number (247871925).

Almost surely, 2^1643036644 is an apocalyptic number.

It is an amenable number.

1643036644 is a deficient number, since it is larger than the sum of its proper divisors (1331426456).

1643036644 is a wasteful number, since it uses less digits than its factorization.

1643036644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14164142 (or 14164140 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 37.

The square root of 1643036644 is about 40534.3884128033. The cubic root of 1643036644 is about 1180.0011117484.

The spelling of 1643036644 in words is "one billion, six hundred forty-three million, thirty-six thousand, six hundred forty-four".