1243663421 has 16 divisors (see below), whose sum is σ = 1669815168. Its totient is φ = 894542400.

The previous prime is 1243663417. The next prime is 1243663439.

1243663421 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 1243663421 - 2² = 1243663417 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243663471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 620210 + ... + 622211.

It is an arithmetic number, because the mean of its divisors is an integer number (104363448).

Almost surely, 2^1243663421 is an apocalyptic number.

1243663421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1243663421 is a deficient number, since it is larger than the sum of its proper divisors (426151747).

1243663421 is a wasteful number, since it uses less digits than its factorization.

1243663421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242452.

The product of its digits is 20736, while the sum is 32.

The square root of 1243663421 is about 35265.6124432853. The cubic root of 1243663421 is about 1075.3940278297.

It can be divided in two parts, 12436 and 63421, that added together give a palindrome (75857).

The spelling of 1243663421 in words is "one billion, two hundred forty-three million, six hundred sixty-three thousand, four hundred twenty-one".