1256851537920 has 1024 divisors, whose sum is σ = 5091471820800. Its totient is φ = 291184312320.

The previous prime is 1256851537891. The next prime is 1256851537951. The reversal of 1256851537920 is 297351586521.

1256851537920 is a `hidden beast` number, since 1 + 2 + 5 + 6 + 8 + 515 + 37 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1024).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1119190479 + ... + 1119191601.

It is an arithmetic number, because the mean of its divisors is an integer number (4972140450).

Almost surely, 2^{1256851537920} is an apocalyptic number.

1256851537920 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 1256851537920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2545735910400).

1256851537920 is an abundant number, since it is smaller than the sum of its proper divisors (3834620282880).

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

1256851537920 is a wasteful number, since it uses less digits than its factorization.

1256851537920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1201 (or 1167 counting only the distinct ones).

The product of its (nonzero) digits is 4536000, while the sum is 54.

The spelling of 1256851537920 in words is "one trillion, two hundred fifty-six billion, eight hundred fifty-one million, five hundred thirty-seven thousand, nine hundred twenty".