1256332891 has 8 divisors (see below), whose sum is σ = 1407587184. Its totient is φ = 1111252320.

The previous prime is 1256332871. The next prime is 1256332927. The reversal of 1256332891 is 1982336521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1256332891 - 2⁹ = 1256332379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256332871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1543000 + ... + 1543813.

It is an arithmetic number, because the mean of its divisors is an integer number (175948398).

Almost surely, 2^1256332891 is an apocalyptic number.

1256332891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1256332891 is a deficient number, since it is larger than the sum of its proper divisors (151254293).

1256332891 is a wasteful number, since it uses less digits than its factorization.

1256332891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3086861.

The product of its digits is 77760, while the sum is 40.

The square root of 1256332891 is about 35444.7865136750. The cubic root of 1256332891 is about 1079.0334548079.

It can be divided in two parts, 12563 and 32891, that added together give a palindrome (45454).

The spelling of 1256332891 in words is "one billion, two hundred fifty-six million, three hundred thirty-two thousand, eight hundred ninety-one".