1225085861 has 2 divisors, whose sum is σ = 1225085862. Its totient is φ = 1225085860.

The previous prime is 1225085843. The next prime is 1225085899. The reversal of 1225085861 is 1685805221.

It is an a-pointer prime, because the next prime (1225085899) can be obtained adding 1225085861 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1126877761 + 98208100 = 33569^2 + 9910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1225085861 is a prime.

It is a super-2 number, since 2×1225085861² = 3001670733644222642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225085261) 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, 612542930 + 612542931.

It is an arithmetic number, because the mean of its divisors is an integer number (612542931).

Almost surely, 2^1225085861 is an apocalyptic number.

It is an amenable number.

1225085861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225085861 is an equidigital number, since it uses as much as digits as its factorization.

1225085861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38400, while the sum is 38.

The square root of 1225085861 is about 35001.2265642220. The cubic root of 1225085861 is about 1070.0124786736.

The spelling of 1225085861 in words is "one billion, two hundred twenty-five million, eighty-five thousand, eight hundred sixty-one".