21444004073 has 2 divisors, whose sum is σ = 21444004074. Its totient is φ = 21444004072.

The previous prime is 21444004013. The next prime is 21444004091. The reversal of 21444004073 is 37040044412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18475061929 + 2968942144 = 135923^2 + 54488^2 .

It is a cyclic number.

It is not a de Polignac number, because 21444004073 - 2⁶ = 21444004009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21444004013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722002036 + 10722002037.

It is an arithmetic number, because the mean of its divisors is an integer number (10722002037).

Almost surely, 2^21444004073 is an apocalyptic number.

It is an amenable number.

21444004073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21444004073 is an equidigital number, since it uses as much as digits as its factorization.

21444004073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 29.

Adding to 21444004073 its reverse (37040044412), we get a palindrome (58484048485).

The spelling of 21444004073 in words is "twenty-one billion, four hundred forty-four million, four thousand, seventy-three".