161541700 has 36 divisors (see below), whose sum is σ = 355363540. Its totient is φ = 63728640.

The previous prime is 161541689. The next prime is 161541703. The reversal of 161541700 is 7145161.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 5391684 + 156150016 = 2322^2 + 12496^2 .

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

It is not an unprimeable number, because it can be changed into a prime (161541703) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3765 + ... + 18364.

Almost surely, 2^161541700 is an apocalyptic number.

161541700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161541700 is an abundant number, since it is smaller than the sum of its proper divisors (193821840).

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

161541700 is a wasteful number, since it uses less digits than its factorization.

161541700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22216 (or 22209 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 161541700 is about 12709.9055858020. The cubic root of 161541700 is about 544.6216266612.

Adding to 161541700 its reverse (7145161), we get a palindrome (168686861).

The spelling of 161541700 in words is "one hundred sixty-one million, five hundred forty-one thousand, seven hundred".