1661200 has 30 divisors (see below), whose sum is σ = 3991994. Its totient is φ = 664320.

The previous prime is 1661173. The next prime is 1661237. The reversal of 1661200 is 21661.

It can be written as a sum of positive squares in 3 ways, for example, as 12544 + 1648656 = 112^2 + 1284^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1677 + ... + 2476.

2^1661200 is an apocalyptic number.

1661200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661200 is an abundant number, since it is smaller than the sum of its proper divisors (2330794).

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

1661200 is a wasteful number, since it uses less digits than its factorization.

1661200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4171 (or 4160 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1661200 is about 1288.8754788574. The cubic root of 1661200 is about 118.4333391627.

Adding to 1661200 its reverse (21661), we get a palindrome (1682861).

It can be divided in two parts, 16 and 61200, that added together give a palindrome (61216).

The spelling of 1661200 in words is "one million, six hundred sixty-one thousand, two hundred".