20001867021 has 24 divisors (see below), whose sum is σ = 30612773880. Its totient is φ = 12541295616.

The previous prime is 20001866959. The next prime is 20001867029. The reversal of 20001867021 is 12076810002.

It can be written as a sum of positive squares in 4 ways, for example, as 15826898025 + 4174968996 = 125805^2 + 64614^2 .

It is not a de Polignac number, because 20001867021 - 2⁶ = 20001866957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001867029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 173635 + ... + 264863.

It is an arithmetic number, because the mean of its divisors is an integer number (1275532245).

Almost surely, 2^20001867021 is an apocalyptic number.

It is an amenable number.

20001867021 is a deficient number, since it is larger than the sum of its proper divisors (10610906859).

20001867021 is a wasteful number, since it uses less digits than its factorization.

20001867021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92685 (or 92682 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The spelling of 20001867021 in words is "twenty billion, one million, eight hundred sixty-seven thousand, twenty-one".