21002003331 has 4 divisors (see below), whose sum is σ = 28002671112. Its totient is φ = 14001335552.

The previous prime is 21002003329. The next prime is 21002003339. The reversal of 21002003331 is 13330020012.

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 21002003331 - 2¹ = 21002003329 is a prime.

It is a super-2 number, since 2×21002003331² (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 21002003331.

It is not an unprimeable number, because it can be changed into a prime (21002003339) 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, 3500333886 + ... + 3500333891.

It is an arithmetic number, because the mean of its divisors is an integer number (7000667778).

Almost surely, 2^21002003331 is an apocalyptic number.

21002003331 is a deficient number, since it is larger than the sum of its proper divisors (7000667781).

21002003331 is an equidigital number, since it uses as much as digits as its factorization.

21002003331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7000667780.

The product of its (nonzero) digits is 108, while the sum is 15.

Adding to 21002003331 its reverse (13330020012), we get a palindrome (34332023343).

The spelling of 21002003331 in words is "twenty-one billion, two million, three thousand, three hundred thirty-one".