21033032231 has 4 divisors (see below), whose sum is σ = 21034425000. Its totient is φ = 21031639464.

The previous prime is 21033032221. The next prime is 21033032239. The reversal of 21033032231 is 13223033012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21033032231 is a prime.

It is a super-2 number, since 2×21033032231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033032239) 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, 673481 + ... + 704018.

It is an arithmetic number, because the mean of its divisors is an integer number (5258606250).

Almost surely, 2^21033032231 is an apocalyptic number.

21033032231 is a deficient number, since it is larger than the sum of its proper divisors (1392769).

21033032231 is a wasteful number, since it uses less digits than its factorization.

21033032231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1392768.

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

Adding to 21033032231 its reverse (13223033012), we get a palindrome (34256065243).

The spelling of 21033032231 in words is "twenty-one billion, thirty-three million, thirty-two thousand, two hundred thirty-one".