21203212113 has 24 divisors (see below), whose sum is σ = 30941913600. Its totient is φ = 13990741920.

The previous prime is 21203212109. The next prime is 21203212139. The reversal of 21203212113 is 31121230212.

It is not a de Polignac number, because 21203212113 - 2² = 21203212109 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21203212103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 351568 + ... + 407438.

It is an arithmetic number, because the mean of its divisors is an integer number (1289246400).

Almost surely, 2^21203212113 is an apocalyptic number.

It is an amenable number.

21203212113 is a deficient number, since it is larger than the sum of its proper divisors (9738701487).

21203212113 is a wasteful number, since it uses less digits than its factorization.

21203212113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56309 (or 56306 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21203212113 its reverse (31121230212), we get a palindrome (52324442325).

The spelling of 21203212113 in words is "twenty-one billion, two hundred three million, two hundred twelve thousand, one hundred thirteen".