1221440043 has 8 divisors (see below), whose sum is σ = 1632264768. Its totient is φ = 812454344.

The previous prime is 1221439993. The next prime is 1221440053. The reversal of 1221440043 is 3400441221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221440043 - 2⁸ = 1221439787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221440053) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 458205 + ... + 460862.

It is an arithmetic number, because the mean of its divisors is an integer number (204033096).

Almost surely, 2^1221440043 is an apocalyptic number.

1221440043 is a deficient number, since it is larger than the sum of its proper divisors (410824725).

1221440043 is an equidigital number, since it uses as much as digits as its factorization.

1221440043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 919513.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 1221440043 is about 34949.1064692647. The cubic root of 1221440043 is about 1068.9499825356.

Adding to 1221440043 its reverse (3400441221), we get a palindrome (4621881264).

The spelling of 1221440043 in words is "one billion, two hundred twenty-one million, four hundred forty thousand, forty-three".