2120000021 has 8 divisors (see below), whose sum is σ = 2194219800. Its totient is φ = 2045854720.

The previous prime is 2120000017. The next prime is 2120000023. The reversal of 2120000021 is 1200000212.

It can be written as a sum of positive squares in 4 ways, for example, as 12180100 + 2107819921 = 3490^2 + 45911^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2120000021 - 2² = 2120000017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2119999963 and 2120000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120000023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42785 + ... + 77913.

It is an arithmetic number, because the mean of its divisors is an integer number (274277475).

Almost surely, 2^2120000021 is an apocalyptic number.

It is an amenable number.

2120000021 is a deficient number, since it is larger than the sum of its proper divisors (74219779).

2120000021 is a wasteful number, since it uses less digits than its factorization.

2120000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37239.

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

The square root of 2120000021 is about 46043.4579609308. The cubic root of 2120000021 is about 1284.6316619542.

Adding to 2120000021 its reverse (1200000212), we get a palindrome (3320000233).

It can be divided in two parts, 2 and 120000021, that multiplied together give a palindrome (240000042).

The spelling of 2120000021 in words is "two billion, one hundred twenty million, twenty-one", and thus it is an aban number.