1990442707021 has 2 divisors, whose sum is σ = 1990442707022. Its totient is φ = 1990442707020.

The previous prime is 1990442706983. The next prime is 1990442707051. The reversal of 1990442707021 is 1207072440991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1964653558921 + 25789148100 = 1401661^2 + 160590^2 .

It is a cyclic number.

It is not a de Polignac number, because 1990442707021 - 2³¹ = 1988295223373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990442707051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995221353510 + 995221353511.

It is an arithmetic number, because the mean of its divisors is an integer number (995221353511).

Almost surely, 2^{1990442707021} is an apocalyptic number.

It is an amenable number.

1990442707021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990442707021 is an equidigital number, since it uses as much as digits as its factorization.

1990442707021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 46.

The spelling of 1990442707021 in words is "one trillion, nine hundred ninety billion, four hundred forty-two million, seven hundred seven thousand, twenty-one".