1236256440 has 128 divisors (see below), whose sum is σ = 3995136000. Its totient is φ = 305141760.

The previous prime is 1236256423. The next prime is 1236256447. The reversal of 1236256440 is 446526321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1236256447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 78336 + ... + 92784.

It is an arithmetic number, because the mean of its divisors is an integer number (31212000).

Almost surely, 2^1236256440 is an apocalyptic number.

1236256440 is a gapful number since it is divisible by the number (10) 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 1236256440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1997568000).

1236256440 is an abundant number, since it is smaller than the sum of its proper divisors (2758879560).

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

1236256440 is a wasteful number, since it uses less digits than its factorization.

1236256440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14517 (or 14513 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 1236256440 is about 35160.4385638177. The cubic root of 1236256440 is about 1073.2548399663.

The spelling of 1236256440 in words is "one billion, two hundred thirty-six million, two hundred fifty-six thousand, four hundred forty".