21203136893 has 2 divisors, whose sum is σ = 21203136894. Its totient is φ = 21203136892.

The previous prime is 21203136869. The next prime is 21203136907. The reversal of 21203136893 is 39863130212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18921928249 + 2281208644 = 137557^2 + 47762^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203136893 - 2⁸ = 21203136637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203136833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601568446 + 10601568447.

It is an arithmetic number, because the mean of its divisors is an integer number (10601568447).

Almost surely, 2^21203136893 is an apocalyptic number.

It is an amenable number.

21203136893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203136893 is an equidigital number, since it uses as much as digits as its factorization.

21203136893 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 38.

The spelling of 21203136893 in words is "twenty-one billion, two hundred three million, one hundred thirty-six thousand, eight hundred ninety-three".