1661140 has 24 divisors (see below), whose sum is σ = 3757320. Its totient is φ = 613248.

The previous prime is 1661137. The next prime is 1661141. The reversal of 1661140 is 411661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 93636 + 1567504 = 306^2 + 1252^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661141) 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, 2935 + ... + 3454.

It is an arithmetic number, because the mean of its divisors is an integer number (156555).

2^1661140 is an apocalyptic number.

1661140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661140 is an abundant number, since it is smaller than the sum of its proper divisors (2096180).

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

1661140 is a wasteful number, since it uses less digits than its factorization.

1661140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6411 (or 6409 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1661140 is about 1288.8522025430. The cubic root of 1661140 is about 118.4319132686.

The spelling of 1661140 in words is "one million, six hundred sixty-one thousand, one hundred forty".