21203031449 has 2 divisors, whose sum is σ = 21203031450. Its totient is φ = 21203031448.

The previous prime is 21203031401. The next prime is 21203031491. The reversal of 21203031449 is 94413030212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18096975625 + 3106055824 = 134525^2 + 55732^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203031449 - 2²⁰ = 21201982873 is a prime.

It is not a weakly prime, because it can be changed into another prime (21203031049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601515724 + 10601515725.

It is an arithmetic number, because the mean of its divisors is an integer number (10601515725).

Almost surely, 2^21203031449 is an apocalyptic number.

It is an amenable number.

21203031449 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203031449 is an equidigital number, since it uses as much as digits as its factorization.

21203031449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21203031449 in words is "twenty-one billion, two hundred three million, thirty-one thousand, four hundred forty-nine".