20001011021 has 2 divisors, whose sum is σ = 20001011022. Its totient is φ = 20001011020.

The previous prime is 20001010999. The next prime is 20001011089. The reversal of 20001011021 is 12011010002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19103109796 + 897901225 = 138214^2 + 29965^2 .

It is a cyclic number.

It is not a de Polignac number, because 20001011021 - 2¹⁸ = 20000748877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001011221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000505510 + 10000505511.

It is an arithmetic number, because the mean of its divisors is an integer number (10000505511).

Almost surely, 2^20001011021 is an apocalyptic number.

It is an amenable number.

20001011021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001011021 is an equidigital number, since it uses as much as digits as its factorization.

20001011021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 20001011021 its reverse (12011010002), we get a palindrome (32012021023).

The spelling of 20001011021 in words is "twenty billion, one million, eleven thousand, twenty-one".