1661869 has 8 divisors (see below), whose sum is σ = 1919808. Its totient is φ = 1421760.

The previous prime is 1661861. The next prime is 1661887. The reversal of 1661869 is 9681661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661869 - 2³ = 1661861 is a prime.

It is a super-2 number, since 2×1661869² = 5523617146322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661861) 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 7 ways as a sum of consecutive naturals, for example, 4257 + ... + 4630.

It is an arithmetic number, because the mean of its divisors is an integer number (239976).

2^1661869 is an apocalyptic number.

It is an amenable number.

1661869 is a deficient number, since it is larger than the sum of its proper divisors (257939).

1661869 is a wasteful number, since it uses less digits than its factorization.

1661869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8915.

The product of its digits is 15552, while the sum is 37.

The square root of 1661869 is about 1289.1349812956. The cubic root of 1661869 is about 118.4492355569.

The spelling of 1661869 in words is "one million, six hundred sixty-one thousand, eight hundred sixty-nine".