1261587312 has 100 divisors (see below), whose sum is σ = 3667577760. Its totient is φ = 418666752.

The previous prime is 1261587311. The next prime is 1261587331. The reversal of 1261587312 is 2137851621.

1261587312 is a `hidden beast` number, since 1 + 2 + 61 + 587 + 3 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261587311) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 307708 + ... + 311780.

Almost surely, 2^1261587312 is an apocalyptic number.

1261587312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261587312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1833788880).

1261587312 is an abundant number, since it is smaller than the sum of its proper divisors (2405990448).

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

1261587312 is a wasteful number, since it uses less digits than its factorization.

1261587312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4332 (or 4317 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 1261587312 is about 35518.8303861487. The cubic root of 1261587312 is about 1080.5356602044.

The spelling of 1261587312 in words is "one billion, two hundred sixty-one million, five hundred eighty-seven thousand, three hundred twelve".