21204302473 has 2 divisors, whose sum is σ = 21204302474. Its totient is φ = 21204302472.

The previous prime is 21204302401. The next prime is 21204302479. The reversal of 21204302473 is 37420340212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11148825744 + 10055476729 = 105588^2 + 100277^2 .

It is a cyclic number.

It is not a de Polignac number, because 21204302473 - 2⁹ = 21204301961 is a prime.

It is not a weakly prime, because it can be changed into another prime (21204302479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602151236 + 10602151237.

It is an arithmetic number, because the mean of its divisors is an integer number (10602151237).

Almost surely, 2^21204302473 is an apocalyptic number.

It is an amenable number.

21204302473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204302473 is an equidigital number, since it uses as much as digits as its factorization.

21204302473 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 28.

Adding to 21204302473 its reverse (37420340212), we get a palindrome (58624642685).

The spelling of 21204302473 in words is "twenty-one billion, two hundred four million, three hundred two thousand, four hundred seventy-three".