21021333031 has 4 divisors (see below), whose sum is σ = 22127719000. Its totient is φ = 19914947064.

The previous prime is 21021333001. The next prime is 21021333041. The reversal of 21021333031 is 13033312012.

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 21021333031 - 2¹⁵ = 21021300263 is a prime.

It is a super-2 number, since 2×21021333031² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1106385949 = 21021333031 / (2 + 1 + 0 + 2 + 1 + 3 + 3 + 3 + 0 + 3 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021333001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553192956 + ... + 553192993.

It is an arithmetic number, because the mean of its divisors is an integer number (5531929750).

Almost surely, 2^21021333031 is an apocalyptic number.

21021333031 is a deficient number, since it is larger than the sum of its proper divisors (1106385969).

21021333031 is a wasteful number, since it uses less digits than its factorization.

21021333031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106385968.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21021333031 its reverse (13033312012), we get a palindrome (34054645043).

The spelling of 21021333031 in words is "twenty-one billion, twenty-one million, three hundred thirty-three thousand, thirty-one".