20001002021 has 16 divisors (see below), whose sum is σ = 26854493568. Its totient is φ = 14386334400.

The previous prime is 20001001957. The next prime is 20001002029. The reversal of 20001002021 is 12020010002.

It is a cyclic number.

It is not a de Polignac number, because 20001002021 - 2⁶ = 20001001957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001002029) 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 15 ways as a sum of consecutive naturals, for example, 9989510 + ... + 9991511.

It is an arithmetic number, because the mean of its divisors is an integer number (1678405848).

Almost surely, 2^20001002021 is an apocalyptic number.

It is an amenable number.

20001002021 is a deficient number, since it is larger than the sum of its proper divisors (6853491547).

20001002021 is a wasteful number, since it uses less digits than its factorization.

20001002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19981052.

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 20001002021 its reverse (12020010002), we get a palindrome (32021012023).

The spelling of 20001002021 in words is "twenty billion, one million, two thousand, twenty-one".