1989392146781 has 8 divisors (see below), whose sum is σ = 2161381803000. Its totient is φ = 1820110989312.

The previous prime is 1989392146759. The next prime is 1989392146823. The reversal of 1989392146781 is 1876412939891.

It can be written as a sum of positive squares in 4 ways, for example, as 488448629881 + 1500943516900 = 698891^2 + 1225130^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1989392146781 - 2⁶ = 1989392146717 is a prime.

It is a super-2 number, since 2×1989392146781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989392146711) by changing a digit.

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, 677123156 + ... + 677126093.

It is an arithmetic number, because the mean of its divisors is an integer number (270172725375).

Almost surely, 2^{1989392146781} is an apocalyptic number.

It is an amenable number.

1989392146781 is a deficient number, since it is larger than the sum of its proper divisors (171989656219).

1989392146781 is a wasteful number, since it uses less digits than its factorization.

1989392146781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354249375.

The product of its digits is 47029248, while the sum is 68.

The spelling of 1989392146781 in words is "one trillion, nine hundred eighty-nine billion, three hundred ninety-two million, one hundred forty-six thousand, seven hundred eighty-one".