1213563656 has 16 divisors (see below), whose sum is σ = 2278433340. Its totient is φ = 605981440.

The previous prime is 1213563653. The next prime is 1213563677. The reversal of 1213563656 is 6563653121.

It can be written as a sum of positive squares in 2 ways, for example, as 902041156 + 311522500 = 30034^2 + 17650^2 .

It is not an unprimeable number, because it can be changed into a prime (1213563653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93581 + ... + 105756.

Almost surely, 2^1213563656 is an apocalyptic number.

It is an amenable number.

1213563656 is a deficient number, since it is larger than the sum of its proper divisors (1064869684).

1213563656 is a wasteful number, since it uses less digits than its factorization.

1213563656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200104 (or 200100 counting only the distinct ones).

The product of its digits is 97200, while the sum is 38.

The square root of 1213563656 is about 34836.2405549164. The cubic root of 1213563656 is about 1066.6473381046.

The spelling of 1213563656 in words is "one billion, two hundred thirteen million, five hundred sixty-three thousand, six hundred fifty-six".