1661142 has 16 divisors (see below), whose sum is σ = 3796992. Its totient is φ = 474600.

The previous prime is 1661141. The next prime is 1661159. The reversal of 1661142 is 2411661.

It is a Harshad number since it is a multiple of its sum of digits (21).

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19734 + ... + 19817.

It is an arithmetic number, because the mean of its divisors is an integer number (237312).

2^1661142 is an apocalyptic number.

1661142 is an abundant number, since it is smaller than the sum of its proper divisors (2135850).

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

1661142 is a wasteful number, since it uses less digits than its factorization.

1661142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39563.

The product of its digits is 288, while the sum is 21.

The square root of 1661142 is about 1288.8529784269. The cubic root of 1661142 is about 118.4319607989.

It can be divided in two parts, 16611 and 42, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 1661142 in words is "one million, six hundred sixty-one thousand, one hundred forty-two".