1661964 has 12 divisors (see below), whose sum is σ = 3877944. Its totient is φ = 553984.

The previous prime is 1661953. The next prime is 1661969. The reversal of 1661964 is 4691661.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (1661969) 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, 69237 + ... + 69260.

It is an arithmetic number, because the mean of its divisors is an integer number (323162).

2^1661964 is an apocalyptic number.

It is an amenable number.

1661964 is an abundant number, since it is smaller than the sum of its proper divisors (2215980).

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

1661964 is a wasteful number, since it uses less digits than its factorization.

1661964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138504 (or 138502 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 1661964 is about 1289.1718271821. The cubic root of 1661964 is about 118.4514925465.

The spelling of 1661964 in words is "one million, six hundred sixty-one thousand, nine hundred sixty-four".