1661984 has 24 divisors (see below), whose sum is σ = 3302208. Its totient is φ = 823360.

The previous prime is 1661983. The next prime is 1662007. The reversal of 1661984 is 4891661.

It is not an unprimeable number, because it can be changed into a prime (1661983) 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, 5189 + ... + 5499.

It is an arithmetic number, because the mean of its divisors is an integer number (137592).

2^1661984 is an apocalyptic number.

It is an amenable number.

1661984 is a deficient number, since it is larger than the sum of its proper divisors (1640224).

1661984 is a wasteful number, since it uses less digits than its factorization.

1661984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488 (or 480 counting only the distinct ones).

The product of its digits is 10368, while the sum is 35.

The square root of 1661984 is about 1289.1795840766. The cubic root of 1661984 is about 118.4519676912.

The spelling of 1661984 in words is "one million, six hundred sixty-one thousand, nine hundred eighty-four".