1213132421 has 4 divisors (see below), whose sum is σ = 1217419392. Its totient is φ = 1208845452.

The previous prime is 1213132411. The next prime is 1213132429. The reversal of 1213132421 is 1242313121.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1213132421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1213132393 and 1213132402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213132429) 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, 2143061 + ... + 2143626.

It is an arithmetic number, because the mean of its divisors is an integer number (304354848).

Almost surely, 2^1213132421 is an apocalyptic number.

It is an amenable number.

1213132421 is a deficient number, since it is larger than the sum of its proper divisors (4286971).

1213132421 is an equidigital number, since it uses as much as digits as its factorization.

1213132421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4286970.

The product of its digits is 288, while the sum is 20.

The square root of 1213132421 is about 34830.0505454701. The cubic root of 1213132421 is about 1066.5209801788.

Adding to 1213132421 its reverse (1242313121), we get a palindrome (2455445542).

The spelling of 1213132421 in words is "one billion, two hundred thirteen million, one hundred thirty-two thousand, four hundred twenty-one".