21420213331 has 24 divisors (see below), whose sum is σ = 24717713328. Its totient is φ = 18406440000.

The previous prime is 21420213289. The next prime is 21420213341. The reversal of 21420213331 is 13331202412.

It is not a de Polignac number, because 21420213331 - 2¹⁷ = 21420082259 is a prime.

It is a super-2 number, since 2×21420213331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21420213341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1824781 + ... + 1836481.

It is an arithmetic number, because the mean of its divisors is an integer number (1029904722).

Almost surely, 2^21420213331 is an apocalyptic number.

21420213331 is a deficient number, since it is larger than the sum of its proper divisors (3297499997).

21420213331 is a wasteful number, since it uses less digits than its factorization.

21420213331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12211 (or 12192 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21420213331 its reverse (13331202412), we get a palindrome (34751415743).

The spelling of 21420213331 in words is "twenty-one billion, four hundred twenty million, two hundred thirteen thousand, three hundred thirty-one".