213331421 has 8 divisors (see below), whose sum is σ = 217518840. Its totient is φ = 209184768.

The previous prime is 213331409. The next prime is 213331423. The reversal of 213331421 is 124133312.

It can be written as a sum of positive squares in 4 ways, for example, as 61795321 + 151536100 = 7861^2 + 12310^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-213331421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213331393 and 213331402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213331423) 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, 485 + ... + 20661.

It is an arithmetic number, because the mean of its divisors is an integer number (27189855).

Almost surely, 2^213331421 is an apocalyptic number.

It is an amenable number.

213331421 is a deficient number, since it is larger than the sum of its proper divisors (4187419).

213331421 is a wasteful number, since it uses less digits than its factorization.

213331421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20383.

The product of its digits is 432, while the sum is 20.

The square root of 213331421 is about 14605.8694024012. The cubic root of 213331421 is about 597.5188474649.

Adding to 213331421 its reverse (124133312), we get a palindrome (337464733).

The spelling of 213331421 in words is "two hundred thirteen million, three hundred thirty-one thousand, four hundred twenty-one".