1221243623 has 2 divisors, whose sum is σ = 1221243624. Its totient is φ = 1221243622.

The previous prime is 1221243587. The next prime is 1221243659. The reversal of 1221243623 is 3263421221.

It is a balanced prime because it is at equal distance from previous prime (1221243587) and next prime (1221243659).

It is an emirp because it is prime and its reverse (3263421221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221243623 - 2¹² = 1221239527 is a prime.

It is a super-2 number, since 2×1221243623² = 2982871973436332258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221243592 and 1221243601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221243223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610621811 + 610621812.

It is an arithmetic number, because the mean of its divisors is an integer number (610621812).

Almost surely, 2^1221243623 is an apocalyptic number.

1221243623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221243623 is an equidigital number, since it uses as much as digits as its factorization.

1221243623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 26.

The square root of 1221243623 is about 34946.2962701343. The cubic root of 1221243623 is about 1068.8926801155.

Adding to 1221243623 its reverse (3263421221), we get a palindrome (4484664844).

The spelling of 1221243623 in words is "one billion, two hundred twenty-one million, two hundred forty-three thousand, six hundred twenty-three".