1263965989 has 16 divisors (see below), whose sum is σ = 1549505664. Its totient is φ = 1014552000.

The previous prime is 1263965977. The next prime is 1263966001. The reversal of 1263965989 is 9895693621.

It is an interprime number because it is at equal distance from previous prime (1263965977) and next prime (1263966001).

It is not a de Polignac number, because 1263965989 - 2¹¹ = 1263963941 is a prime.

It is a super-2 number, since 2×1263965989² = 3195220042697496242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1263965939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188862 + ... + 195439.

It is an arithmetic number, because the mean of its divisors is an integer number (96844104).

Almost surely, 2^1263965989 is an apocalyptic number.

It is an amenable number.

1263965989 is a deficient number, since it is larger than the sum of its proper divisors (285539675).

1263965989 is a wasteful number, since it uses less digits than its factorization.

1263965989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384348.

The product of its digits is 6298560, while the sum is 58.

The square root of 1263965989 is about 35552.2993489873. The cubic root of 1263965989 is about 1081.2143374073.

The spelling of 1263965989 in words is "one billion, two hundred sixty-three million, nine hundred sixty-five thousand, nine hundred eighty-nine".