21202230021 has 16 divisors (see below), whose sum is σ = 32316211200. Its totient is φ = 12112540848.

The previous prime is 21202230013. The next prime is 21202230073. The reversal of 21202230021 is 12003220212.

It is a happy number.

It is not a de Polignac number, because 21202230021 - 2³ = 21202230013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202230121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38101 + ... + 209418.

It is an arithmetic number, because the mean of its divisors is an integer number (2019763200).

Almost surely, 2^21202230021 is an apocalyptic number.

21202230021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21202230021 is a deficient number, since it is larger than the sum of its proper divisors (11113981179).

21202230021 is a wasteful number, since it uses less digits than its factorization.

21202230021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251608.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21202230021 its reverse (12003220212), we get a palindrome (33205450233).

The spelling of 21202230021 in words is "twenty-one billion, two hundred two million, two hundred thirty thousand, twenty-one".