1224561643 has 4 divisors (see below), whose sum is σ = 1231640208. Its totient is φ = 1217483080.

The previous prime is 1224561631. The next prime is 1224561649. The reversal of 1224561643 is 3461654221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1224561643 - 2²⁵ = 1191007211 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1224561599 and 1224561608.

It is not an unprimeable number, because it can be changed into a prime (1224561649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3539023 + ... + 3539368.

It is an arithmetic number, because the mean of its divisors is an integer number (307910052).

Almost surely, 2^1224561643 is an apocalyptic number.

1224561643 is a deficient number, since it is larger than the sum of its proper divisors (7078565).

1224561643 is an equidigital number, since it uses as much as digits as its factorization.

1224561643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7078564.

The product of its digits is 34560, while the sum is 34.

The square root of 1224561643 is about 34993.7371968185. The cubic root of 1224561643 is about 1069.8598363582.

The spelling of 1224561643 in words is "one billion, two hundred twenty-four million, five hundred sixty-one thousand, six hundred forty-three".