2120021001 has 12 divisors (see below), whose sum is σ = 3499717312. Its totient is φ = 1211440536.

The previous prime is 2120020997. The next prime is 2120021003. The reversal of 2120021001 is 1001200212.

It is not a de Polignac number, because 2120021001 - 2² = 2120020997 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (2120021003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16825501 + ... + 16825626.

Almost surely, 2^2120021001 is an apocalyptic number.

2120021001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2120021001 is a deficient number, since it is larger than the sum of its proper divisors (1379696311).

2120021001 is a wasteful number, since it uses less digits than its factorization.

2120021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33651140 (or 33651137 counting only the distinct ones).

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

The square root of 2120021001 is about 46043.6857886073. The cubic root of 2120021001 is about 1284.6358996088.

Adding to 2120021001 its reverse (1001200212), we get a palindrome (3121221213).

The spelling of 2120021001 in words is "two billion, one hundred twenty million, twenty-one thousand, one".