1663634643 has 48 divisors (see below), whose sum is σ = 2549922816. Its totient is φ = 956704320.

The previous prime is 1663634593. The next prime is 1663634659. The reversal of 1663634643 is 3464363661.

It is not a de Polignac number, because 1663634643 - 2⁹ = 1663634131 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1663634595 and 1663634604.

It is not an unprimeable number, because it can be changed into a prime (1663634143) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2740446 + ... + 2741052.

It is an arithmetic number, because the mean of its divisors is an integer number (53123392).

Almost surely, 2^1663634643 is an apocalyptic number.

1663634643 is a deficient number, since it is larger than the sum of its proper divisors (886288173).

1663634643 is a wasteful number, since it uses less digits than its factorization.

1663634643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 801 counting only the distinct ones).

The product of its digits is 559872, while the sum is 42.

The square root of 1663634643 is about 40787.6775877225. The cubic root of 1663634643 is about 1184.9116927554.

The spelling of 1663634643 in words is "one billion, six hundred sixty-three million, six hundred thirty-four thousand, six hundred forty-three".