1256640135744 has 336 divisors, whose sum is σ = 3996197638272. Its totient is φ = 347228356608.

The previous prime is 1256640135731. The next prime is 1256640135749. The reversal of 1256640135744 is 4475310466521.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 1256640135693 and 1256640135702.

It is not an unprimeable number, because it can be changed into a prime (1256640135749) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 58121224 + ... + 58142840.

It is an arithmetic number, because the mean of its divisors is an integer number (11893445352).

Almost surely, 2^{1256640135744} is an apocalyptic number.

1256640135744 is a gapful number since it is divisible by the number (14) 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 1256640135744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1998098819136).

1256640135744 is an abundant number, since it is smaller than the sum of its proper divisors (2739557502528).

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

1256640135744 is a wasteful number, since it uses less digits than its factorization.

1256640135744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21850 (or 21833 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 48.

The spelling of 1256640135744 in words is "one trillion, two hundred fifty-six billion, six hundred forty million, one hundred thirty-five thousand, seven hundred forty-four".