21302421123 has 4 divisors (see below), whose sum is σ = 28403228168. Its totient is φ = 14201614080.

The previous prime is 21302421103. The next prime is 21302421131. The reversal of 21302421123 is 32112420312.

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

It is not a de Polignac number, because 21302421123 - 2¹³ = 21302412931 is a prime.

It is a super-2 number, since 2×21302421123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21302421123.

It is not an unprimeable number, because it can be changed into a prime (21302421103) 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, 3550403518 + ... + 3550403523.

It is an arithmetic number, because the mean of its divisors is an integer number (7100807042).

Almost surely, 2^21302421123 is an apocalyptic number.

21302421123 is a deficient number, since it is larger than the sum of its proper divisors (7100807045).

21302421123 is an equidigital number, since it uses as much as digits as its factorization.

21302421123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7100807044.

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21302421123 its reverse (32112420312), we get a palindrome (53414841435).

The spelling of 21302421123 in words is "twenty-one billion, three hundred two million, four hundred twenty-one thousand, one hundred twenty-three".