165638004 has 96 divisors (see below), whose sum is σ = 470889216. Its totient is φ = 44236800.

The previous prime is 165637993. The next prime is 165638009. The reversal of 165638004 is 400836561.

It is a super-3 number, since 3×165638004³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165638009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 275304 + ... + 275904.

It is an arithmetic number, because the mean of its divisors is an integer number (4905096).

Almost surely, 2^165638004 is an apocalyptic number.

165638004 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165638004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235444608).

165638004 is an abundant number, since it is smaller than the sum of its proper divisors (305251212).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165638004 is a wasteful number, since it uses less digits than its factorization.

165638004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 165638004 is about 12870.0428903714. The cubic root of 165638004 is about 549.1866810836.

The spelling of 165638004 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, four".