120120021 has 18 divisors (see below), whose sum is σ = 201835062. Its totient is φ = 68639760.

The previous prime is 120119999. The next prime is 120120031. The reversal of 120120021 is 120021021.

It can be written as a sum of positive squares in only one way, i.e., 95765796 + 24354225 = 9786^2 + 4935^2 .

It is not a de Polignac number, because 120120021 - 2¹¹ = 120117973 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 = 120119985 and 120120012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (120120031) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 135750 + ... + 136631.

It is an arithmetic number, because the mean of its divisors is an integer number (11213059).

Almost surely, 2^120120021 is an apocalyptic number.

It is an amenable number.

120120021 is a deficient number, since it is larger than the sum of its proper divisors (81715041).

120120021 is a wasteful number, since it uses less digits than its factorization.

120120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272401 (or 272391 counting only the distinct ones).

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

The square root of 120120021 is about 10959.9279650917. The cubic root of 120120021 is about 493.4068029834.

Adding to 120120021 its reverse (120021021), we get a palindrome (240141042).

The spelling of 120120021 in words is "one hundred twenty million, one hundred twenty thousand, twenty-one".