1225981 has 2 divisors, whose sum is σ = 1225982. Its totient is φ = 1225980.

The previous prime is 1225963. The next prime is 1225997. The reversal of 1225981 is 1895221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1092025 + 133956 = 1045^2 + 366^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225981 - 2⁵ = 1225949 is a prime.

It is a super-2 number, since 2×1225981² = 3006058824722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225381) 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, 612990 + 612991.

It is an arithmetic number, because the mean of its divisors is an integer number (612991).

2^1225981 is an apocalyptic number.

It is an amenable number.

1225981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225981 is an equidigital number, since it uses as much as digits as its factorization.

1225981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 28.

The square root of 1225981 is about 1107.2402629962. The cubic root of 1225981 is about 107.0273025503.

The spelling of 1225981 in words is "one million, two hundred twenty-five thousand, nine hundred eighty-one".