1225556851 has 2 divisors, whose sum is σ = 1225556852. Its totient is φ = 1225556850.

The previous prime is 1225556749. The next prime is 1225556881. The reversal of 1225556851 is 1586555221.

It is a strong prime.

It is an emirp because it is prime and its reverse (1586555221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1225556851 - 2⁷ = 1225556723 is a prime.

It is not a weakly prime, because it can be changed into another prime (1225556881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612778425 + 612778426.

It is an arithmetic number, because the mean of its divisors is an integer number (612778426).

Almost surely, 2^1225556851 is an apocalyptic number.

1225556851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225556851 is an equidigital number, since it uses as much as digits as its factorization.

1225556851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120000, while the sum is 40.

The square root of 1225556851 is about 35007.9541104590. The cubic root of 1225556851 is about 1070.1495848752.

The spelling of 1225556851 in words is "one billion, two hundred twenty-five million, five hundred fifty-six thousand, eight hundred fifty-one".