1638161204 has 6 divisors (see below), whose sum is σ = 2866782114. Its totient is φ = 819080600.

The previous prime is 1638161141. The next prime is 1638161219. The reversal of 1638161204 is 4021618361.

It can be written as a sum of positive squares in only one way, i.e., 1360872100 + 277289104 = 36890^2 + 16652^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204770147 + ... + 204770154.

It is an arithmetic number, because the mean of its divisors is an integer number (477797019).

Almost surely, 2^1638161204 is an apocalyptic number.

It is an amenable number.

1638161204 is a deficient number, since it is larger than the sum of its proper divisors (1228620910).

1638161204 is a wasteful number, since it uses less digits than its factorization.

1638161204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409540305 (or 409540303 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1638161204 is about 40474.2041799465. The cubic root of 1638161204 is about 1178.8328025643.

Adding to 1638161204 its reverse (4021618361), we get a palindrome (5659779565).

The spelling of 1638161204 in words is "one billion, six hundred thirty-eight million, one hundred sixty-one thousand, two hundred four".