215243421 has 8 divisors (see below), whose sum is σ = 288352224. Its totient is φ = 142815120.

The previous prime is 215243401. The next prime is 215243429. The reversal of 215243421 is 124342512.

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

It is not a de Polignac number, because 215243421 - 2²⁶ = 148134557 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 215243391 and 215243400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215243429) 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, 169386 + ... + 170651.

It is an arithmetic number, because the mean of its divisors is an integer number (36044028).

Almost surely, 2^215243421 is an apocalyptic number.

It is an amenable number.

215243421 is a deficient number, since it is larger than the sum of its proper divisors (73108803).

215243421 is a wasteful number, since it uses less digits than its factorization.

215243421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340251.

The product of its digits is 1920, while the sum is 24.

The square root of 215243421 is about 14671.1765376878. The cubic root of 215243421 is about 599.2986443755.

Adding to 215243421 its reverse (124342512), we get a palindrome (339585933).

Subtracting from 215243421 its reverse (124342512), we obtain a palindrome (90900909).

The spelling of 215243421 in words is "two hundred fifteen million, two hundred forty-three thousand, four hundred twenty-one".