165640520100 has 144 divisors (see below), whose sum is σ = 524474306496. Its totient is φ = 40028352000.

The previous prime is 165640520069. The next prime is 165640520159. The reversal of 165640520100 is 1025046561.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 966930 + ... + 1125270.

It is an arithmetic number, because the mean of its divisors is an integer number (3642182684).

Almost surely, 2^165640520100 is an apocalyptic number.

165640520100 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 165640520100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262237153248).

165640520100 is an abundant number, since it is smaller than the sum of its proper divisors (358833786396).

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

165640520100 is a wasteful number, since it uses less digits than its factorization.

165640520100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158686 (or 158679 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

Adding to 165640520100 its reverse (1025046561), we get a palindrome (166665566661).

The spelling of 165640520100 in words is "one hundred sixty-five billion, six hundred forty million, five hundred twenty thousand, one hundred".