165531400 has 48 divisors (see below), whose sum is σ = 386582400. Its totient is φ = 65916480.

The previous prime is 165531361. The next prime is 165531427. The reversal of 165531400 is 4135561.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46069 + ... + 49531.

It is an arithmetic number, because the mean of its divisors is an integer number (8053800).

Almost surely, 2^165531400 is an apocalyptic number.

165531400 is a gapful number since it is divisible by the number (10) 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 165531400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193291200).

165531400 is an abundant number, since it is smaller than the sum of its proper divisors (221051000).

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

165531400 is a wasteful number, since it uses less digits than its factorization.

165531400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3718 (or 3709 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 165531400 is about 12865.9006680450. The cubic root of 165531400 is about 549.0688376340.

Adding to 165531400 its reverse (4135561), we get a palindrome (169666961).

The spelling of 165531400 in words is "one hundred sixty-five million, five hundred thirty-one thousand, four hundred".