1989878836398 has 32 divisors (see below), whose sum is σ = 4014346156800. Its totient is φ = 657542382336.

The previous prime is 1989878836333. The next prime is 1989878836399. The reversal of 1989878836398 is 8936388789891.

It is a super-2 number, since 2×1989878836398² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989878836399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1211338 + ... + 2333901.

It is an arithmetic number, because the mean of its divisors is an integer number (125448317400).

Almost surely, 2^{1989878836398} is an apocalyptic number.

1989878836398 is an abundant number, since it is smaller than the sum of its proper divisors (2024467320402).

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

1989878836398 is a wasteful number, since it uses less digits than its factorization.

1989878836398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3546056.

The product of its digits is 9029615616, while the sum is 87.

The spelling of 1989878836398 in words is "one trillion, nine hundred eighty-nine billion, eight hundred seventy-eight million, eight hundred thirty-six thousand, three hundred ninety-eight".