1990324781538 has 16 divisors (see below), whose sum is σ = 3981245638080. Its totient is φ = 663342248016.

The previous prime is 1990324781503. The next prime is 1990324781563. The reversal of 1990324781538 is 8351874230991.

It is a happy number.

It is a super-2 number, since 2×1990324781538² (a number of 25 digits) contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 24793045 + ... + 24873192.

It is an arithmetic number, because the mean of its divisors is an integer number (248827852380).

Almost surely, 2^{1990324781538} is an apocalyptic number.

1990324781538 is an abundant number, since it is smaller than the sum of its proper divisors (1990920856542).

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

1990324781538 is a wasteful number, since it uses less digits than its factorization.

1990324781538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49672921.

The product of its (nonzero) digits is 13063680, while the sum is 60.

The spelling of 1990324781538 in words is "one trillion, nine hundred ninety billion, three hundred twenty-four million, seven hundred eighty-one thousand, five hundred thirty-eight".