1990435561920 has 504 divisors, whose sum is σ = 7442462436864. Its totient is φ = 485344161792.

The previous prime is 1990435561879. The next prime is 1990435561943. The reversal of 1990435561920 is 291655340991.

1990435561920 is a `hidden beast` number, since 19 + 9 + 0 + 4 + 3 + 5 + 5 + 619 + 2 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3076407037 + ... + 3076407683.

Almost surely, 2^{1990435561920} is an apocalyptic number.

1990435561920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1990435561920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3721231218432).

1990435561920 is an abundant number, since it is smaller than the sum of its proper divisors (5452026874944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1990435561920 is a wasteful number, since it uses less digits than its factorization.

1990435561920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1457 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 2624400, while the sum is 54.

The spelling of 1990435561920 in words is "one trillion, nine hundred ninety billion, four hundred thirty-five million, five hundred sixty-one thousand, nine hundred twenty".