210120120021 has 16 divisors (see below), whose sum is σ = 321952012928. Its totient is φ = 119405275200.

The previous prime is 210120119987. The next prime is 210120120043. The reversal of 210120120021 is 120021021012.

It is not a de Polignac number, because 210120120021 - 2⁹ = 210120119509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210120119979 and 210120120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210120120421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27636310 + ... + 27643911.

It is an arithmetic number, because the mean of its divisors is an integer number (20122000808).

Almost surely, 2^210120120021 is an apocalyptic number.

210120120021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

210120120021 is a deficient number, since it is larger than the sum of its proper divisors (111831892907).

210120120021 is a wasteful number, since it uses less digits than its factorization.

210120120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55280412.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 210120120021 its reverse (120021021012), we get a palindrome (330141141033).

Subtracting from 210120120021 its reverse (120021021012), we obtain a palindrome (90099099009).

The spelling of 210120120021 in words is "two hundred ten billion, one hundred twenty million, one hundred twenty thousand, twenty-one".