2120404561 has 4 divisors (see below), whose sum is σ = 2313168624. Its totient is φ = 1927640500.

The previous prime is 2120404553. The next prime is 2120404567. The reversal of 2120404561 is 1654040212.

It is a happy number.

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 2120404561 - 2³ = 2120404553 is a prime.

It is a super-2 number, since 2×2120404561² = 8992231004619205442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2120404567) 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 3 ways as a sum of consecutive naturals, for example, 96382015 + ... + 96382036.

It is an arithmetic number, because the mean of its divisors is an integer number (578292156).

Almost surely, 2^2120404561 is an apocalyptic number.

It is an amenable number.

2120404561 is a deficient number, since it is larger than the sum of its proper divisors (192764063).

2120404561 is a wasteful number, since it uses less digits than its factorization.

2120404561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192764062.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 2120404561 is about 46047.8507750362. The cubic root of 2120404561 is about 1284.7133682176.

Adding to 2120404561 its reverse (1654040212), we get a palindrome (3774444773).

The spelling of 2120404561 in words is "two billion, one hundred twenty million, four hundred four thousand, five hundred sixty-one".