21203240203 has 8 divisors (see below), whose sum is σ = 21478865408. Its totient is φ = 20928956904.

The previous prime is 21203240197. The next prime is 21203240231. The reversal of 21203240203 is 30204230212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21203240203 - 2³³ = 12613305611 is a prime.

It is a super-2 number, since 2×21203240203² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203240503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303651 + ... + 366892.

It is an arithmetic number, because the mean of its divisors is an integer number (2684858176).

Almost surely, 2^21203240203 is an apocalyptic number.

21203240203 is a deficient number, since it is larger than the sum of its proper divisors (275625205).

21203240203 is a wasteful number, since it uses less digits than its factorization.

21203240203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670953.

The product of its (nonzero) digits is 576, while the sum is 19.

Adding to 21203240203 its reverse (30204230212), we get a palindrome (51407470415).

Subtracting 21203240203 from its reverse (30204230212), we obtain a palindrome (9000990009).

The spelling of 21203240203 in words is "twenty-one billion, two hundred three million, two hundred forty thousand, two hundred three".