2631221 has 2 divisors, whose sum is σ = 2631222. Its totient is φ = 2631220.

The previous prime is 2631217. The next prime is 2631241. The reversal of 2631221 is 1221362.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2283121 + 348100 = 1511^2 + 590^2 .

It is a cyclic number.

It is not a de Polignac number, because 2631221 - 2² = 2631217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2631221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2631241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1315610 + 1315611.

It is an arithmetic number, because the mean of its divisors is an integer number (1315611).

2^2631221 is an apocalyptic number.

It is an amenable number.

2631221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2631221 is an equidigital number, since it uses as much as digits as its factorization.

2631221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 17.

The square root of 2631221 is about 1622.1038807672. The cubic root of 2631221 is about 138.0550959726.

Adding to 2631221 its reverse (1221362), we get a palindrome (3852583).

It can be divided in two parts, 263 and 1221, that multiplied together give a palindrome (321123).

The spelling of 2631221 in words is "two million, six hundred thirty-one thousand, two hundred twenty-one".