20010120100021 has 4 divisors (see below), whose sum is σ = 20010638495232. Its totient is φ = 20009601704812.

The previous prime is 20010120099941. The next prime is 20010120100027. The reversal of 20010120100021 is 12000102101002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20010120100021 - 2³⁵ = 19975760361653 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20010120099980 and 20010120100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20010120100027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259139701 + ... + 259216906.

It is an arithmetic number, because the mean of its divisors is an integer number (5002659623808).

Almost surely, 2^{20010120100021} is an apocalyptic number.

It is an amenable number.

20010120100021 is a deficient number, since it is larger than the sum of its proper divisors (518395211).

20010120100021 is an equidigital number, since it uses as much as digits as its factorization.

20010120100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518395210.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20010120100021 its reverse (12000102101002), we get a palindrome (32010222201023).

The spelling of 20010120100021 in words is "twenty trillion, ten billion, one hundred twenty million, one hundred thousand, twenty-one".