1243421013 has 4 divisors (see below), whose sum is σ = 1657894688. Its totient is φ = 828947340.

The previous prime is 1243420993. The next prime is 1243421033. The reversal of 1243421013 is 3101243421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3101243421 = 3 ⋅1033747807.

It is an interprime number because it is at equal distance from previous prime (1243420993) and next prime (1243421033).

It is not a de Polignac number, because 1243421013 - 2²¹ = 1241323861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243421033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207236833 + ... + 207236838.

It is an arithmetic number, because the mean of its divisors is an integer number (414473672).

Almost surely, 2^1243421013 is an apocalyptic number.

It is an amenable number.

1243421013 is a deficient number, since it is larger than the sum of its proper divisors (414473675).

1243421013 is an equidigital number, since it uses as much as digits as its factorization.

1243421013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414473674.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1243421013 is about 35262.1753866661. The cubic root of 1243421013 is about 1075.3241533363.

Adding to 1243421013 its reverse (3101243421), we get a palindrome (4344664434).

The spelling of 1243421013 in words is "one billion, two hundred forty-three million, four hundred twenty-one thousand, thirteen".