1256243136 has 28 divisors (see below), whose sum is σ = 3323810472. Its totient is φ = 418747648.

The previous prime is 1256243117. The next prime is 1256243147. The reversal of 1256243136 is 6313426521.

It is a super-2 number, since 2×1256243136² = 3156293633494228992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1256243097 and 1256243106.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3271275 + ... + 3271658.

Almost surely, 2^1256243136 is an apocalyptic number.

1256243136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1256243136 is an abundant number, since it is smaller than the sum of its proper divisors (2067567336).

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

1256243136 is an equidigital number, since it uses as much as digits as its factorization.

1256243136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6542948 (or 6542938 counting only the distinct ones).

The product of its digits is 25920, while the sum is 33.

The square root of 1256243136 is about 35443.5203669162. The cubic root of 1256243136 is about 1079.0077580745.

Adding to 1256243136 its reverse (6313426521), we get a palindrome (7569669657).

The spelling of 1256243136 in words is "one billion, two hundred fifty-six million, two hundred forty-three thousand, one hundred thirty-six".