1213631 has 2 divisors, whose sum is σ = 1213632. Its totient is φ = 1213630.

The previous prime is 1213627. The next prime is 1213633. The reversal of 1213631 is 1363121.

It is a strong prime.

It is an emirp because it is prime and its reverse (1363121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1213631 - 2² = 1213627 is a prime.

It is a super-2 number, since 2×1213631² = 2945800408322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1213633, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213633) 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, 606815 + 606816.

It is an arithmetic number, because the mean of its divisors is an integer number (606816).

2^1213631 is an apocalyptic number.

1213631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213631 is an equidigital number, since it uses as much as digits as its factorization.

1213631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108, while the sum is 17.

The square root of 1213631 is about 1101.6492182178. The cubic root of 1213631 is about 106.6667068142. Note that the first 3 decimals are identical.

Adding to 1213631 its reverse (1363121), we get a palindrome (2576752).

It can be divided in two parts, 12136 and 31, that added together give a cube (12167 = 23³).

The spelling of 1213631 in words is "one million, two hundred thirteen thousand, six hundred thirty-one".