1661812 has 12 divisors (see below), whose sum is σ = 2979396. Its totient is φ = 810560.

The previous prime is 1661789. The next prime is 1661813. The reversal of 1661812 is 2181661.

It can be written as a sum of positive squares in 2 ways, for example, as 633616 + 1028196 = 796^2 + 1014^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4903 + ... + 5230.

It is an arithmetic number, because the mean of its divisors is an integer number (248283).

2^1661812 is an apocalyptic number.

It is an amenable number.

1661812 is a deficient number, since it is larger than the sum of its proper divisors (1317584).

1661812 is a wasteful number, since it uses less digits than its factorization.

1661812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10178 (or 10176 counting only the distinct ones).

The product of its digits is 576, while the sum is 25.

The square root of 1661812 is about 1289.1128732582. The cubic root of 1661812 is about 118.4478813219.

The spelling of 1661812 in words is "one million, six hundred sixty-one thousand, eight hundred twelve".