1256732887 has 4 divisors (see below), whose sum is σ = 1273948480. Its totient is φ = 1239517296.

The previous prime is 1256732881. The next prime is 1256732891. The reversal of 1256732887 is 7882376521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1256732887 - 2²⁷ = 1122515159 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 1256732887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256732881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8607687 + ... + 8607832.

It is an arithmetic number, because the mean of its divisors is an integer number (318487120).

Almost surely, 2^1256732887 is an apocalyptic number.

1256732887 is a deficient number, since it is larger than the sum of its proper divisors (17215593).

1256732887 is an equidigital number, since it uses as much as digits as its factorization.

1256732887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17215592.

The product of its digits is 1128960, while the sum is 49.

The square root of 1256732887 is about 35450.4285869720. The cubic root of 1256732887 is about 1079.1479582359.

It can be divided in two parts, 12567 and 32887, that added together give a palindrome (45454).

The spelling of 1256732887 in words is "one billion, two hundred fifty-six million, seven hundred thirty-two thousand, eight hundred eighty-seven".