21001033020 has 96 divisors (see below), whose sum is σ = 64783950336. Its totient is φ = 5040736000.

The previous prime is 21001032991. The next prime is 21001033033. The reversal of 21001033020 is 2033010012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21001032987 and 21001033005.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 90864 + ... + 224183.

It is an arithmetic number, because the mean of its divisors is an integer number (674832816).

Almost surely, 2^21001033020 is an apocalyptic number.

21001033020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001033020 is an abundant number, since it is smaller than the sum of its proper divisors (43782917316).

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

21001033020 is a wasteful number, since it uses less digits than its factorization.

21001033020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315171 (or 315169 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 21001033020 its reverse (2033010012), we get a palindrome (23034043032).

The spelling of 21001033020 in words is "twenty-one billion, one million, thirty-three thousand, twenty".