1256704789 has 2 divisors, whose sum is σ = 1256704790. Its totient is φ = 1256704788.

The previous prime is 1256704769. The next prime is 1256704811. The reversal of 1256704789 is 9874076521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1254363889 + 2340900 = 35417^2 + 1530^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256704789 - 2²¹ = 1254607637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1256704739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628352394 + 628352395.

It is an arithmetic number, because the mean of its divisors is an integer number (628352395).

Almost surely, 2^1256704789 is an apocalyptic number.

It is an amenable number.

1256704789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256704789 is an equidigital number, since it uses as much as digits as its factorization.

1256704789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 846720, while the sum is 49.

The square root of 1256704789 is about 35450.0322848936. The cubic root of 1256704789 is about 1079.1399156556.

The spelling of 1256704789 in words is "one billion, two hundred fifty-six million, seven hundred four thousand, seven hundred eighty-nine".