1985642564198 has 4 divisors (see below), whose sum is σ = 2978463846300. Its totient is φ = 992821282098.

The previous prime is 1985642564197. The next prime is 1985642564263. The reversal of 1985642564198 is 8914652465891.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1985642564197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496410641048 + ... + 496410641051.

It is an arithmetic number, because the mean of its divisors is an integer number (744615961575).

Almost surely, 2^{1985642564198} is an apocalyptic number.

1985642564198 is a deficient number, since it is larger than the sum of its proper divisors (992821282102).

1985642564198 is an equidigital number, since it uses as much as digits as its factorization.

1985642564198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992821282101.

The product of its digits is 149299200, while the sum is 68.

The spelling of 1985642564198 in words is "one trillion, nine hundred eighty-five billion, six hundred forty-two million, five hundred sixty-four thousand, one hundred ninety-eight".