21220343243 has 8 divisors (see below), whose sum is σ = 23326180416. Its totient is φ = 19143958600.

The previous prime is 21220343203. The next prime is 21220343273. The reversal of 21220343243 is 34234302212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220343243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21220343203) 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, 7361621 + ... + 7364502.

It is an arithmetic number, because the mean of its divisors is an integer number (2915772552).

Almost surely, 2^21220343243 is an apocalyptic number.

21220343243 is a deficient number, since it is larger than the sum of its proper divisors (2105837173).

21220343243 is a wasteful number, since it uses less digits than its factorization.

21220343243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14726265.

The product of its (nonzero) digits is 6912, while the sum is 26.

Adding to 21220343243 its reverse (34234302212), we get a palindrome (55454645455).

It can be divided in two parts, 21220 and 343243, that added together give a palindrome (364463).

The spelling of 21220343243 in words is "twenty-one billion, two hundred twenty million, three hundred forty-three thousand, two hundred forty-three".