1243425421 has 16 divisors (see below), whose sum is σ = 1477440000. Its totient is φ = 1045668624.

The previous prime is 1243425397. The next prime is 1243425437. The reversal of 1243425421 is 1245243421.

It is not a de Polignac number, because 1243425421 - 2⁵ = 1243425389 is a prime.

It is a super-2 number, since 2×1243425421² = 3092213555178054482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243425421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243425481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16021 + ... + 52378.

It is an arithmetic number, because the mean of its divisors is an integer number (92340000).

Almost surely, 2^1243425421 is an apocalyptic number.

It is an amenable number.

1243425421 is a deficient number, since it is larger than the sum of its proper divisors (234014579).

1243425421 is an frugal number, since it uses more digits than its factorization.

1243425421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68473 (or 68459 counting only the distinct ones).

The product of its digits is 7680, while the sum is 28.

The square root of 1243425421 is about 35262.2378898447. The cubic root of 1243425421 is about 1075.3254240304.

Adding to 1243425421 its reverse (1245243421), we get a palindrome (2488668842).

The spelling of 1243425421 in words is "one billion, two hundred forty-three million, four hundred twenty-five thousand, four hundred twenty-one".