21312242243 has 4 divisors (see below), whose sum is σ = 21312584208. Its totient is φ = 21311900280.

The previous prime is 21312242233. The next prime is 21312242291. The reversal of 21312242243 is 34224221312.

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 21312242243 - 2¹⁴ = 21312225859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312242213) 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, 48023 + ... + 211968.

It is an arithmetic number, because the mean of its divisors is an integer number (5328146052).

Almost surely, 2^21312242243 is an apocalyptic number.

21312242243 is a deficient number, since it is larger than the sum of its proper divisors (341965).

21312242243 is an equidigital number, since it uses as much as digits as its factorization.

21312242243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341964.

The product of its digits is 4608, while the sum is 26.

Adding to 21312242243 its reverse (34224221312), we get a palindrome (55536463555).

The spelling of 21312242243 in words is "twenty-one billion, three hundred twelve million, two hundred forty-two thousand, two hundred forty-three".