1296643869 has 36 divisors (see below), whose sum is σ = 1964106144. Its totient is φ = 855886824.

The previous prime is 1296643813. The next prime is 1296643889. The reversal of 1296643869 is 9683466921.

It is not a de Polignac number, because 1296643869 - 2⁸ = 1296643613 is a prime.

It is a super-2 number, since 2×1296643869² = 3362570646030578322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1296643889) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 701104 + ... + 702950.

It is an arithmetic number, because the mean of its divisors is an integer number (54558504).

Almost surely, 2^1296643869 is an apocalyptic number.

It is an amenable number.

1296643869 is a deficient number, since it is larger than the sum of its proper divisors (667462275).

1296643869 is an frugal number, since it uses more digits than its factorization.

1296643869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1978 (or 1957 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 1296643869 is about 36008.9415145738. The cubic root of 1296643869 is about 1090.4528794520.

The spelling of 1296643869 in words is "one billion, two hundred ninety-six million, six hundred forty-three thousand, eight hundred sixty-nine".