1984198861 has 8 divisors (see below), whose sum is σ = 2089274400. Its totient is φ = 1879187760.

The previous prime is 1984198849. The next prime is 1984198871. The reversal of 1984198861 is 1688914891.

It is a happy number.

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 1984198861 - 2⁵ = 1984198829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1984198871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55251 + ... + 83791.

It is an arithmetic number, because the mean of its divisors is an integer number (261159300).

Almost surely, 2^1984198861 is an apocalyptic number.

It is an amenable number.

1984198861 is a deficient number, since it is larger than the sum of its proper divisors (105075539).

1984198861 is a wasteful number, since it uses less digits than its factorization.

1984198861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32219.

The product of its digits is 995328, while the sum is 55.

The square root of 1984198861 is about 44544.3471273292. The cubic root of 1984198861 is about 1256.5942419530.

The spelling of 1984198861 in words is "one billion, nine hundred eighty-four million, one hundred ninety-eight thousand, eight hundred sixty-one".