21653221203 has 12 divisors (see below), whose sum is σ = 31398578328. Its totient is φ = 14379310080.

The previous prime is 21653221201. The next prime is 21653221207. The reversal of 21653221203 is 30212235612.

It is a happy number.

21653221203 is a `hidden beast` number, since 2 + 1 + 6 + 532 + 2 + 120 + 3 = 666.

It is not a de Polignac number, because 21653221203 - 2¹ = 21653221201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21653221201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4678453 + ... + 4683078.

It is an arithmetic number, because the mean of its divisors is an integer number (2616548194).

Almost surely, 2^21653221203 is an apocalyptic number.

21653221203 is a deficient number, since it is larger than the sum of its proper divisors (9745357125).

21653221203 is a wasteful number, since it uses less digits than its factorization.

21653221203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9361794 (or 9361791 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 21653221203 its reverse (30212235612), we get a palindrome (51865456815).

The spelling of 21653221203 in words is "twenty-one billion, six hundred fifty-three million, two hundred twenty-one thousand, two hundred three".