21203311323 has 16 divisors (see below), whose sum is σ = 29506867200. Its totient is φ = 13517923584.

The previous prime is 21203311321. The next prime is 21203311351. The reversal of 21203311323 is 32311330212.

It is not a de Polignac number, because 21203311323 - 2¹ = 21203311321 is a prime.

It is a super-2 number, since 2×21203311323² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21203311323.

It is not an unprimeable number, because it can be changed into a prime (21203311321) 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, 299115 + ... + 363147.

It is an arithmetic number, because the mean of its divisors is an integer number (1844179200).

Almost surely, 2^21203311323 is an apocalyptic number.

21203311323 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21203311323 is a deficient number, since it is larger than the sum of its proper divisors (8303555877).

21203311323 is a wasteful number, since it uses less digits than its factorization.

21203311323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68858.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21203311323 its reverse (32311330212), we get a palindrome (53514641535).

The spelling of 21203311323 in words is "twenty-one billion, two hundred three million, three hundred eleven thousand, three hundred twenty-three".