18165581652100 has 27 divisors (see below), whose sum is σ = 39419404673061. Its totient is φ = 7266215612400.

The previous prime is 18165581652059. The next prime is 18165581652109. The reversal of 18165581652100 is 125618556181.

The square root of 18165581652100 is 4262110.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 6539609394756 + 11625972257344 = 2557266^2 + 3409688^2 .

It is a super-2 number, since 2×18165581652100² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18165581652109) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 42407995 + ... + 42834205.

Almost surely, 2^{18165581652100} is an apocalyptic number.

18165581652100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18165581652100 is the 4262110-th square number.

It is an amenable number.

18165581652100 is an abundant number, since it is smaller than the sum of its proper divisors (21253823020961).

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

18165581652100 is an frugal number, since it uses more digits than its factorization.

18165581652100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852436 (or 426218 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 49.

Multiplying 18165581652100 by its sum of digits (49), we get a square (890113500952900 = 29834770²).

The spelling of 18165581652100 in words is "eighteen trillion, one hundred sixty-five billion, five hundred eighty-one million, six hundred fifty-two thousand, one hundred".