1256545139 has 2 divisors, whose sum is σ = 1256545140. Its totient is φ = 1256545138.

The previous prime is 1256545117. The next prime is 1256545151. The reversal of 1256545139 is 9315456521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1256545139 - 2²⁴ = 1239767923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1256545096 and 1256545105.

It is not a weakly prime, because it can be changed into another prime (1256545109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628272569 + 628272570.

It is an arithmetic number, because the mean of its divisors is an integer number (628272570).

Almost surely, 2^1256545139 is an apocalyptic number.

1256545139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256545139 is an equidigital number, since it uses as much as digits as its factorization.

1256545139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 41.

The square root of 1256545139 is about 35447.7804523781. The cubic root of 1256545139 is about 1079.0942162506.

The spelling of 1256545139 in words is "one billion, two hundred fifty-six million, five hundred forty-five thousand, one hundred thirty-nine".