1256172947 has 2 divisors, whose sum is σ = 1256172948. Its totient is φ = 1256172946.

The previous prime is 1256172941. The next prime is 1256172997. The reversal of 1256172947 is 7492716521.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1256172947 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1256172898 and 1256172907.

It is not a weakly prime, because it can be changed into another prime (1256172941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628086473 + 628086474.

It is an arithmetic number, because the mean of its divisors is an integer number (628086474).

Almost surely, 2^1256172947 is an apocalyptic number.

1256172947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256172947 is an equidigital number, since it uses as much as digits as its factorization.

1256172947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 44.

The square root of 1256172947 is about 35442.5302003116. The cubic root of 1256172947 is about 1078.9876622072.

The spelling of 1256172947 in words is "one billion, two hundred fifty-six million, one hundred seventy-two thousand, nine hundred forty-seven".