21203453205 has 96 divisors (see below), whose sum is σ = 40515845760. Its totient is φ = 10172874240.

The previous prime is 21203453203. The next prime is 21203453267. The reversal of 21203453205 is 50235430212.

It is a happy number.

21203453205 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 3 + 453 + 205 = 666.

It is not a de Polignac number, because 21203453205 - 2¹ = 21203453203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203453203) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 25576731 + ... + 25577559.

It is an arithmetic number, because the mean of its divisors is an integer number (422040060).

Almost surely, 2^21203453205 is an apocalyptic number.

It is an amenable number.

21203453205 is a deficient number, since it is larger than the sum of its proper divisors (19312392555).

21203453205 is a wasteful number, since it uses less digits than its factorization.

21203453205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331 (or 1328 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

Adding to 21203453205 its reverse (50235430212), we get a palindrome (71438883417).

The spelling of 21203453205 in words is "twenty-one billion, two hundred three million, four hundred fifty-three thousand, two hundred five".