1261431872 has 56 divisors (see below), whose sum is σ = 2667707136. Its totient is φ = 590425088.

The previous prime is 1261431863. The next prime is 1261431877. The reversal of 1261431872 is 2781341621.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1261431877) 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, 60068 + ... + 78300.

Almost surely, 2^1261431872 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 1261431872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1333853568).

1261431872 is an abundant number, since it is smaller than the sum of its proper divisors (1406275264).

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

1261431872 is a wasteful number, since it uses less digits than its factorization.

1261431872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18315 (or 18305 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 1261431872 is about 35516.6421836299. The cubic root of 1261431872 is about 1080.4912808314.

The spelling of 1261431872 in words is "one billion, two hundred sixty-one million, four hundred thirty-one thousand, eight hundred seventy-two".