21423402073 has 2 divisors, whose sum is σ = 21423402074. Its totient is φ = 21423402072.

The previous prime is 21423402067. The next prime is 21423402089. The reversal of 21423402073 is 37020432412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18970379289 + 2453022784 = 137733^2 + 49528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21423402073 is a prime.

It is not a weakly prime, because it can be changed into another prime (21423402173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711701036 + 10711701037.

It is an arithmetic number, because the mean of its divisors is an integer number (10711701037).

Almost surely, 2^21423402073 is an apocalyptic number.

It is an amenable number.

21423402073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423402073 is an equidigital number, since it uses as much as digits as its factorization.

21423402073 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21423402073 its reverse (37020432412), we get a palindrome (58443834485).

The spelling of 21423402073 in words is "twenty-one billion, four hundred twenty-three million, four hundred two thousand, seventy-three".