20210100021 has 32 divisors (see below), whose sum is σ = 31892071680. Its totient is φ = 12604866048.

The previous prime is 20210100019. The next prime is 20210100037. The reversal of 20210100021 is 12000101202.

It is not a de Polignac number, because 20210100021 - 2¹ = 20210100019 is a prime.

It is a super-3 number, since 3×20210100021³ (a number of 32 digits) contains 333 as substring.

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 = 20210099976 and 20210100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20210100011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55176 + ... + 208481.

It is an arithmetic number, because the mean of its divisors is an integer number (996627240).

Almost surely, 2^20210100021 is an apocalyptic number.

It is an amenable number.

20210100021 is a deficient number, since it is larger than the sum of its proper divisors (11681971659).

20210100021 is a wasteful number, since it uses less digits than its factorization.

20210100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263850 (or 263844 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20210100021 its reverse (12000101202), we get a palindrome (32210201223).

The spelling of 20210100021 in words is "twenty billion, two hundred ten million, one hundred thousand, twenty-one".