21203023213 has 4 divisors (see below), whose sum is σ = 21458481408. Its totient is φ = 20947565020.

The previous prime is 21203023183. The next prime is 21203023249. The reversal of 21203023213 is 31232030212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21203023213 - 2¹⁷ = 21202892141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203023273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127728973 + ... + 127729138.

It is an arithmetic number, because the mean of its divisors is an integer number (5364620352).

Almost surely, 2^21203023213 is an apocalyptic number.

It is an amenable number.

21203023213 is a deficient number, since it is larger than the sum of its proper divisors (255458195).

21203023213 is an equidigital number, since it uses as much as digits as its factorization.

21203023213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255458194.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21203023213 its reverse (31232030212), we get a palindrome (52435053425).

The spelling of 21203023213 in words is "twenty-one billion, two hundred three million, twenty-three thousand, two hundred thirteen".