1256144240 has 80 divisors (see below), whose sum is σ = 3185212800. Its totient is φ = 457906176.

The previous prime is 1256144237. The next prime is 1256144243. The reversal of 1256144240 is 424416521.

It is an interprime number because it is at equal distance from previous prime (1256144237) and next prime (1256144243).

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256144243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74516 + ... + 89804.

It is an arithmetic number, because the mean of its divisors is an integer number (39815160).

Almost surely, 2^1256144240 is an apocalyptic number.

1256144240 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 1256144240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1592606400).

1256144240 is an abundant number, since it is smaller than the sum of its proper divisors (1929068560).

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

1256144240 is a wasteful number, since it uses less digits than its factorization.

1256144240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15394 (or 15388 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 1256144240 is about 35442.1252184459. The cubic root of 1256144240 is about 1078.9794428679.

The spelling of 1256144240 in words is "one billion, two hundred fifty-six million, one hundred forty-four thousand, two hundred forty".