1223921 has 2 divisors, whose sum is σ = 1223922. Its totient is φ = 1223920.

The previous prime is 1223897. The next prime is 1223939. The reversal of 1223921 is 1293221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1079521 + 144400 = 1039^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 1223921 - 2⁶ = 1223857 is a prime.

It is a super-2 number, since 2×1223921² = 2995965228482, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1223893 and 1223902.

It is not a weakly prime, because it can be changed into another prime (1223941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 611960 + 611961.

It is an arithmetic number, because the mean of its divisors is an integer number (611961).

2^1223921 is an apocalyptic number.

It is an amenable number.

1223921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1223921 is an equidigital number, since it uses as much as digits as its factorization.

1223921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 20.

The square root of 1223921 is about 1106.3096311612. The cubic root of 1223921 is about 106.9673234135.

The spelling of 1223921 in words is "one million, two hundred twenty-three thousand, nine hundred twenty-one".