163641538 has 8 divisors (see below), whose sum is σ = 245526588. Its totient is φ = 81799344.

The previous prime is 163641523. The next prime is 163641539. The reversal of 163641538 is 835146361.

It can be written as a sum of positive squares in 2 ways, for example, as 146724769 + 16916769 = 12113^2 + 4113^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 163641497 and 163641506.

It is not an unprimeable number, because it can be changed into a prime (163641539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1720 + ... + 18172.

Almost surely, 2^163641538 is an apocalyptic number.

163641538 is a deficient number, since it is larger than the sum of its proper divisors (81885050).

163641538 is a wasteful number, since it uses less digits than its factorization.

163641538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21428.

The product of its digits is 51840, while the sum is 37.

The square root of 163641538 is about 12792.2452290440. The cubic root of 163641538 is about 546.9712727511.

Adding to 163641538 its reverse (835146361), we get a palindrome (998787899).

The spelling of 163641538 in words is "one hundred sixty-three million, six hundred forty-one thousand, five hundred thirty-eight".