1512221 has 2 divisors, whose sum is σ = 1512222. Its totient is φ = 1512220.

The previous prime is 1512209. The next prime is 1512223. The reversal of 1512221 is 1222151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1406596 + 105625 = 1186^2 + 325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1512221 is a prime.

It is a Sophie Germain prime.

Together with 1512223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1512196 and 1512205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1512223) 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, 756110 + 756111.

It is an arithmetic number, because the mean of its divisors is an integer number (756111).

2^1512221 is an apocalyptic number.

It is an amenable number.

1512221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1512221 is an equidigital number, since it uses as much as digits as its factorization.

1512221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40, while the sum is 14.

The square root of 1512221 is about 1229.7239527634. The cubic root of 1512221 is about 114.7814627282.

Adding to 1512221 its reverse (1222151), we get a palindrome (2734372).

It can be divided in two parts, 15 and 12221, that multiplied together give a triangular number (183315 = T₆₀₅).

The spelling of 1512221 in words is "one million, five hundred twelve thousand, two hundred twenty-one".