1661913 has 12 divisors (see below), whose sum is σ = 2618928. Its totient is φ = 1007160.

The previous prime is 1661899. The next prime is 1661917. The reversal of 1661913 is 3191661.

It is not a de Polignac number, because 1661913 - 2¹⁰ = 1660889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8295 + ... + 8492.

It is an arithmetic number, because the mean of its divisors is an integer number (218244).

2^1661913 is an apocalyptic number.

It is an amenable number.

1661913 is a deficient number, since it is larger than the sum of its proper divisors (957015).

1661913 is a wasteful number, since it uses less digits than its factorization.

1661913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16804 (or 16801 counting only the distinct ones).

The product of its digits is 972, while the sum is 27.

The square root of 1661913 is about 1289.1520468897. The cubic root of 1661913 is about 118.4502809101.

The spelling of 1661913 in words is "one million, six hundred sixty-one thousand, nine hundred thirteen".