215221423 has 4 divisors (see below), whose sum is σ = 220470768. Its totient is φ = 209972080.

The previous prime is 215221421. The next prime is 215221463. The reversal of 215221423 is 324122512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 215221423 - 2¹ = 215221421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 215221394 and 215221403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215221421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2624611 + ... + 2624692.

It is an arithmetic number, because the mean of its divisors is an integer number (55117692).

Almost surely, 2^215221423 is an apocalyptic number.

215221423 is a deficient number, since it is larger than the sum of its proper divisors (5249345).

215221423 is an equidigital number, since it uses as much as digits as its factorization.

215221423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5249344.

The product of its digits is 960, while the sum is 22.

The square root of 215221423 is about 14670.4268172402. The cubic root of 215221423 is about 599.2782274592.

Adding to 215221423 its reverse (324122512), we get a palindrome (539343935).

The spelling of 215221423 in words is "two hundred fifteen million, two hundred twenty-one thousand, four hundred twenty-three".