1661472 has 60 divisors (see below), whose sum is σ = 4893966. Its totient is φ = 552960.

The previous prime is 1661447. The next prime is 1661479. The reversal of 1661472 is 2741661.

It can be written as a sum of positive squares in only one way, i.e., 1089936 + 571536 = 1044^2 + 756^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661479) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2272 + ... + 2912.

2^1661472 is an apocalyptic number.

1661472 is a gapful number since it is divisible by the number (12) 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 1661472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2446983).

1661472 is an abundant number, since it is smaller than the sum of its proper divisors (3232494).

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

1661472 is an equidigital number, since it uses as much as digits as its factorization.

1661472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663 (or 646 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 1661472 is about 1288.9809928777. The cubic root of 1661472 is about 118.4398027854.

The spelling of 1661472 in words is "one million, six hundred sixty-one thousand, four hundred seventy-two".