21311033020 has 24 divisors (see below), whose sum is σ = 44758111104. Its totient is φ = 8523471936.

The previous prime is 21311032913. The next prime is 21311033033. The reversal of 21311033020 is 2033011312.

It is a junction number, because it is equal to n+sod(n) for n = 21311032985 and 21311033003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143854 + ... + 251626.

It is an arithmetic number, because the mean of its divisors is an integer number (1864921296).

Almost surely, 2^21311033020 is an apocalyptic number.

21311033020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311033020 is an abundant number, since it is smaller than the sum of its proper divisors (23447078084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21311033020 is a wasteful number, since it uses less digits than its factorization.

21311033020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117669 (or 117667 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21311033020 its reverse (2033011312), we get a palindrome (23344044332).

The spelling of 21311033020 in words is "twenty-one billion, three hundred eleven million, thirty-three thousand, twenty".