1291637264 has 40 divisors (see below), whose sum is σ = 2600458560. Its totient is φ = 620751488.

The previous prime is 1291637251. The next prime is 1291637267. The reversal of 1291637264 is 4627361921.

It is not an unprimeable number, because it can be changed into a prime (1291637267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99197 + ... + 111459.

It is an arithmetic number, because the mean of its divisors is an integer number (65011464).

Almost surely, 2^1291637264 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 1291637264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1300229280).

1291637264 is an abundant number, since it is smaller than the sum of its proper divisors (1308821296).

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

1291637264 is a wasteful number, since it uses less digits than its factorization.

1291637264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12527 (or 12521 counting only the distinct ones).

The product of its digits is 108864, while the sum is 41.

The square root of 1291637264 is about 35939.3553642800. The cubic root of 1291637264 is about 1089.0475825970.

The spelling of 1291637264 in words is "one billion, two hundred ninety-one million, six hundred thirty-seven thousand, two hundred sixty-four".