21221001203 has 16 divisors (see below), whose sum is σ = 21537715200. Its totient is φ = 20907222336.

The previous prime is 21221001199. The next prime is 21221001209. The reversal of 21221001203 is 30210012212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21221001203 - 2² = 21221001199 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221001209) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14912150 + ... + 14913572.

It is an arithmetic number, because the mean of its divisors is an integer number (1346107200).

Almost surely, 2^21221001203 is an apocalyptic number.

21221001203 is a deficient number, since it is larger than the sum of its proper divisors (316713997).

21221001203 is a wasteful number, since it uses less digits than its factorization.

21221001203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2306.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21221001203 its reverse (30210012212), we get a palindrome (51431013415).

The spelling of 21221001203 in words is "twenty-one billion, two hundred twenty-one million, one thousand, two hundred three".