21230313021 has 6 divisors (see below), whose sum is σ = 30666007710. Its totient is φ = 14153542008.

The previous prime is 21230312993. The next prime is 21230313029. The reversal of 21230313021 is 12031303212.

21230313021 is a `hidden beast` number, since 212 + 303 + 130 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20509390521 + 720922500 = 143211^2 + 26850^2 .

It is not a de Polignac number, because 21230313021 - 2¹³ = 21230304829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21230312985 and 21230313003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230313029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179461826 + ... + 1179461843.

It is an arithmetic number, because the mean of its divisors is an integer number (5111001285).

Almost surely, 2^21230313021 is an apocalyptic number.

It is an amenable number.

21230313021 is a deficient number, since it is larger than the sum of its proper divisors (9435694689).

21230313021 is a wasteful number, since it uses less digits than its factorization.

21230313021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358923675 (or 2358923672 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21230313021 its reverse (12031303212), we get a palindrome (33261616233).

The spelling of 21230313021 in words is "twenty-one billion, two hundred thirty million, three hundred thirteen thousand, twenty-one".