21033223031 has 4 divisors (see below), whose sum is σ = 21039465864. Its totient is φ = 21026980200.

The previous prime is 21033223027. The next prime is 21033223049. The reversal of 21033223031 is 13032233012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21033223031 - 2² = 21033223027 is a prime.

It is a super-2 number, since 2×21033223031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21033222994 and 21033223012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033222031) 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, 3116360 + ... + 3123101.

It is an arithmetic number, because the mean of its divisors is an integer number (5259866466).

Almost surely, 2^21033223031 is an apocalyptic number.

21033223031 is a deficient number, since it is larger than the sum of its proper divisors (6242833).

21033223031 is an equidigital number, since it uses as much as digits as its factorization.

21033223031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6242832.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21033223031 its reverse (13032233012), we get a palindrome (34065456043).

The spelling of 21033223031 in words is "twenty-one billion, thirty-three million, two hundred twenty-three thousand, thirty-one".