1263639029689 has 9 divisors (see below), whose sum is σ = 1275462081453. Its totient is φ = 1251924606432.

The previous prime is 1263639029677. The next prime is 1263639029701. The reversal of 1263639029689 is 9869209363621.

The square root of 1263639029689 is 1124117.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (1263639029677) and next prime (1263639029701).

It can be written as a sum of positive squares in 4 ways, for example, as 16191290025 + 1247447739664 = 127245^2 + 1116892^2 .

It is not a de Polignac number, because 1263639029689 - 2¹¹ = 1263639027641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1263639029689.

It is not an unprimeable number, because it can be changed into a prime (1263639029629) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 122523597 + ... + 122533909.

Almost surely, 2^{1263639029689} is an apocalyptic number.

1263639029689 is the 1124117-th square number.

1263639029689 is the 562059-th centered octagonal number.

It is an amenable number.

1263639029689 is a deficient number, since it is larger than the sum of its proper divisors (11823051764).

1263639029689 is an frugal number, since it uses more digits than its factorization.

1263639029689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20844 (or 10422 counting only the distinct ones).

The product of its (nonzero) digits is 45349632, while the sum is 64.

Multiplying 1263639029689 by its sum of digits (64), we get a square (80872897900096 = 8992936²).

The spelling of 1263639029689 in words is "one trillion, two hundred sixty-three billion, six hundred thirty-nine million, twenty-nine thousand, six hundred eighty-nine".