1263236864 has 54 divisors (see below), whose sum is σ = 2551230864. Its totient is φ = 624263680.

The previous prime is 1263236851. The next prime is 1263236881. The reversal of 1263236864 is 4686323621.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2930729 + ... + 2931159.

It is an arithmetic number, because the mean of its divisors is an integer number (47245016).

Almost surely, 2^1263236864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1263236864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1275615432).

1263236864 is an abundant number, since it is smaller than the sum of its proper divisors (1287994000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1263236864 is an frugal number, since it uses more digits than its factorization.

1263236864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661 (or 540 counting only the distinct ones).

The product of its digits is 248832, while the sum is 41.

The square root of 1263236864 is about 35542.0436103497. The cubic root of 1263236864 is about 1081.0063961480.

The spelling of 1263236864 in words is "one billion, two hundred sixty-three million, two hundred thirty-six thousand, eight hundred sixty-four".