21230221021 has 8 divisors (see below), whose sum is σ = 21280512704. Its totient is φ = 21179957760.

The previous prime is 21230221013. The next prime is 21230221037. The reversal of 21230221021 is 12012203212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21230221021 - 2³ = 21230221013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230220986 and 21230221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230221091) 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, 2427226 + ... + 2435956.

It is an arithmetic number, because the mean of its divisors is an integer number (2660064088).

Almost surely, 2^21230221021 is an apocalyptic number.

It is an amenable number.

21230221021 is a deficient number, since it is larger than the sum of its proper divisors (50291683).

21230221021 is an equidigital number, since it uses as much as digits as its factorization.

21230221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14211.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21230221021 its reverse (12012203212), we get a palindrome (33242424233).

The spelling of 21230221021 in words is "twenty-one billion, two hundred thirty million, two hundred twenty-one thousand, twenty-one".