2121020990 has 32 divisors (see below), whose sum is σ = 4169926656. Its totient is φ = 770352160.

The previous prime is 2121020989. The next prime is 2121021013. The reversal of 2121020990 is 990201212.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83759 + ... + 106101.

It is an arithmetic number, because the mean of its divisors is an integer number (130310208).

Almost surely, 2^2121020990 is an apocalyptic number.

2121020990 is a deficient number, since it is larger than the sum of its proper divisors (2048905666).

2121020990 is a wasteful number, since it uses less digits than its factorization.

2121020990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23224.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 2121020990 is about 46054.5436412087. The cubic root of 2121020990 is about 1284.8378504134.

The spelling of 2121020990 in words is "two billion, one hundred twenty-one million, twenty thousand, nine hundred ninety".