1638752198 has 4 divisors (see below), whose sum is σ = 2458128300. Its totient is φ = 819376098.

The previous prime is 1638752191. The next prime is 1638752239. The reversal of 1638752198 is 8912578361.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638752191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409688048 + ... + 409688051.

It is an arithmetic number, because the mean of its divisors is an integer number (614532075).

Almost surely, 2^1638752198 is an apocalyptic number.

1638752198 is a deficient number, since it is larger than the sum of its proper divisors (819376102).

1638752198 is an equidigital number, since it uses as much as digits as its factorization.

1638752198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819376101.

The product of its digits is 725760, while the sum is 50.

The square root of 1638752198 is about 40481.5043939822. The cubic root of 1638752198 is about 1178.9745467240.

The spelling of 1638752198 in words is "one billion, six hundred thirty-eight million, seven hundred fifty-two thousand, one hundred ninety-eight".