21423055573 has 2 divisors, whose sum is σ = 21423055574. Its totient is φ = 21423055572.

The previous prime is 21423055519. The next prime is 21423055603. The reversal of 21423055573 is 37555032412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18500896324 + 2922159249 = 136018^2 + 54057^2 .

It is a cyclic number.

It is not a de Polignac number, because 21423055573 - 2⁹ = 21423055061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21423055513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711527786 + 10711527787.

It is an arithmetic number, because the mean of its divisors is an integer number (10711527787).

Almost surely, 2^21423055573 is an apocalyptic number.

It is an amenable number.

21423055573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423055573 is an equidigital number, since it uses as much as digits as its factorization.

21423055573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126000, while the sum is 37.

Adding to 21423055573 its reverse (37555032412), we get a palindrome (58978087985).

The spelling of 21423055573 in words is "twenty-one billion, four hundred twenty-three million, fifty-five thousand, five hundred seventy-three".