1256878291 has 16 divisors (see below), whose sum is σ = 1370557440. Its totient is φ = 1148225760.

The previous prime is 1256878267. The next prime is 1256878297. The reversal of 1256878291 is 1928786521.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1256878291 - 2⁷ = 1256878163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256878297) 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, 168936 + ... + 176218.

It is an arithmetic number, because the mean of its divisors is an integer number (85659840).

Almost surely, 2^1256878291 is an apocalyptic number.

1256878291 is a deficient number, since it is larger than the sum of its proper divisors (113679149).

1256878291 is a wasteful number, since it uses less digits than its factorization.

1256878291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7626.

The product of its digits is 483840, while the sum is 49.

The square root of 1256878291 is about 35452.4793350197. The cubic root of 1256878291 is about 1079.1895757719.

The spelling of 1256878291 in words is "one billion, two hundred fifty-six million, eight hundred seventy-eight thousand, two hundred ninety-one".