21002223243 has 16 divisors (see below), whose sum is σ = 29224200960. Its totient is φ = 13391018784.

The previous prime is 21002223191. The next prime is 21002223251. The reversal of 21002223243 is 34232220012.

It is not a de Polignac number, because 21002223243 - 2¹⁴ = 21002206859 is a prime.

It is a super-2 number, since 2×21002223243² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21002223043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 743268 + ... + 771006.

It is an arithmetic number, because the mean of its divisors is an integer number (1826512560).

Almost surely, 2^21002223243 is an apocalyptic number.

21002223243 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21002223243 is a deficient number, since it is larger than the sum of its proper divisors (8221977717).

21002223243 is a wasteful number, since it uses less digits than its factorization.

21002223243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38738.

The product of its (nonzero) digits is 1152, while the sum is 21.

Adding to 21002223243 its reverse (34232220012), we get a palindrome (55234443255).

The spelling of 21002223243 in words is "twenty-one billion, two million, two hundred twenty-three thousand, two hundred forty-three".