1256405674 has 4 divisors (see below), whose sum is σ = 1884608514. Its totient is φ = 628202836.

The previous prime is 1256405573. The next prime is 1256405687. The reversal of 1256405674 is 4765046521.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4765046521 = 29 ⋅164311949.

It can be written as a sum of positive squares in only one way, i.e., 805140625 + 451265049 = 28375^2 + 21243^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314101417 + ... + 314101420.

Almost surely, 2^1256405674 is an apocalyptic number.

1256405674 is a deficient number, since it is larger than the sum of its proper divisors (628202840).

1256405674 is an equidigital number, since it uses as much as digits as its factorization.

1256405674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628202839.

The product of its (nonzero) digits is 201600, while the sum is 40.

The square root of 1256405674 is about 35445.8132083325. The cubic root of 1256405674 is about 1079.0542915824.

The spelling of 1256405674 in words is "one billion, two hundred fifty-six million, four hundred five thousand, six hundred seventy-four".