213621421 has 8 divisors (see below), whose sum is σ = 230172320. Its totient is φ = 197087472.

The previous prime is 213621409. The next prime is 213621431. The reversal of 213621421 is 124126312.

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

It is a cyclic number.

It is not a de Polignac number, because 213621421 - 2⁹ = 213620909 is a prime.

It is a super-2 number, since 2×213621421² = 91268223020118482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213621392 and 213621401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213621431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36526 + ... + 41968.

It is an arithmetic number, because the mean of its divisors is an integer number (28771540).

Almost surely, 2^213621421 is an apocalyptic number.

It is an amenable number.

213621421 is a deficient number, since it is larger than the sum of its proper divisors (16550899).

213621421 is a wasteful number, since it uses less digits than its factorization.

213621421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8475.

The product of its digits is 576, while the sum is 22.

The square root of 213621421 is about 14615.7935467083. The cubic root of 213621421 is about 597.7894780261.

Adding to 213621421 its reverse (124126312), we get a palindrome (337747733).

The spelling of 213621421 in words is "two hundred thirteen million, six hundred twenty-one thousand, four hundred twenty-one".