1661245 has 8 divisors (see below), whose sum is σ = 2018016. Its totient is φ = 1312656.

The previous prime is 1661243. The next prime is 1661249. The reversal of 1661245 is 5421661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661245 - 2¹ = 1661243 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1587 + ... + 2416.

It is an arithmetic number, because the mean of its divisors is an integer number (252252).

2^1661245 is an apocalyptic number.

It is an amenable number.

1661245 is a deficient number, since it is larger than the sum of its proper divisors (356771).

1661245 is an equidigital number, since it uses as much as digits as its factorization.

1661245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4091.

The product of its digits is 1440, while the sum is 25.

The square root of 1661245 is about 1288.8929358174. The cubic root of 1661245 is about 118.4344085608.

The spelling of 1661245 in words is "one million, six hundred sixty-one thousand, two hundred forty-five".