20010111021 has 64 divisors (see below), whose sum is σ = 31668019200. Its totient is φ = 12458432448.

The previous prime is 20010111013. The next prime is 20010111029. The reversal of 20010111021 is 12011101002.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20010111013) and next prime (20010111029).

It is not a de Polignac number, because 20010111021 - 2³ = 20010111013 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 20010110994 and 20010111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010111029) 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 63 ways as a sum of consecutive naturals, for example, 24137235 + ... + 24138063.

It is an arithmetic number, because the mean of its divisors is an integer number (494812800).

Almost surely, 2^20010111021 is an apocalyptic number.

It is an amenable number.

20010111021 is a deficient number, since it is larger than the sum of its proper divisors (11657908179).

20010111021 is a wasteful number, since it uses less digits than its factorization.

20010111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1735 (or 1729 counting only the distinct ones).

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

Adding to 20010111021 its reverse (12011101002), we get a palindrome (32021212023).

The spelling of 20010111021 in words is "twenty billion, ten million, one hundred eleven thousand, twenty-one".