21031303673 has 2 divisors, whose sum is σ = 21031303674. Its totient is φ = 21031303672.

The previous prime is 21031303663. The next prime is 21031303679. The reversal of 21031303673 is 37630313012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16965583504 + 4065720169 = 130252^2 + 63763^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031303673 - 2²⁰ = 21030255097 is a prime.

It is not a weakly prime, because it can be changed into another prime (21031303679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515651836 + 10515651837.

It is an arithmetic number, because the mean of its divisors is an integer number (10515651837).

Almost surely, 2^21031303673 is an apocalyptic number.

It is an amenable number.

21031303673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031303673 is an equidigital number, since it uses as much as digits as its factorization.

21031303673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 29.

Adding to 21031303673 its reverse (37630313012), we get a palindrome (58661616685).

The spelling of 21031303673 in words is "twenty-one billion, thirty-one million, three hundred three thousand, six hundred seventy-three".