20011011021 has 12 divisors (see below), whose sum is σ = 29378643580. Its totient is φ = 13121974080.

The previous prime is 20011011001. The next prime is 20011011073. The reversal of 20011011021 is 12011011002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8379388521 + 11631622500 = 91539^2 + 107850^2 .

It is not a de Polignac number, because 20011011021 - 2⁵ = 20011010989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011010994 and 20011011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011011001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18224416 + ... + 18225513.

Almost surely, 2^20011011021 is an apocalyptic number.

It is an amenable number.

20011011021 is a deficient number, since it is larger than the sum of its proper divisors (9367632559).

20011011021 is a wasteful number, since it uses less digits than its factorization.

20011011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36449996 (or 36449993 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20011011021 its reverse (12011011002), we get a palindrome (32022022023).

The spelling of 20011011021 in words is "twenty billion, eleven million, eleven thousand, twenty-one".