1256787851 has 16 divisors (see below), whose sum is σ = 1467676800. Its totient is φ = 1064044800.

The previous prime is 1256787841. The next prime is 1256787859. The reversal of 1256787851 is 1587876521.

It is a cyclic number.

It is not a de Polignac number, because 1256787851 - 2¹⁸ = 1256525707 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1256787851.

It is not an unprimeable number, because it can be changed into a prime (1256787859) 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, 38630 + ... + 63291.

It is an arithmetic number, because the mean of its divisors is an integer number (91729800).

Almost surely, 2^1256787851 is an apocalyptic number.

1256787851 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1256787851 is a deficient number, since it is larger than the sum of its proper divisors (210888949).

1256787851 is a wasteful number, since it uses less digits than its factorization.

1256787851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102010.

The product of its digits is 940800, while the sum is 50.

The square root of 1256787851 is about 35451.2038018457. The cubic root of 1256787851 is about 1079.1636904105.

The spelling of 1256787851 in words is "one billion, two hundred fifty-six million, seven hundred eighty-seven thousand, eight hundred fifty-one".