2181669 has 8 divisors (see below), whose sum is σ = 3324480. Its totient is φ = 1246656.

The previous prime is 2181659. The next prime is 2181671. The reversal of 2181669 is 9661812.

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

It is not a de Polignac number, because 2181669 - 2⁷ = 2181541 is a prime.

It is a super-2 number, since 2×2181669² = 9519359251122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51924 + ... + 51965.

It is an arithmetic number, because the mean of its divisors is an integer number (415560).

2^2181669 is an apocalyptic number.

It is an amenable number.

2181669 is a deficient number, since it is larger than the sum of its proper divisors (1142811).

2181669 is a wasteful number, since it uses less digits than its factorization.

2181669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103899.

The product of its digits is 5184, while the sum is 33.

The square root of 2181669 is about 1477.0473926046. The cubic root of 2181669 is about 129.6969073062.

It can be divided in two parts, 2181 and 669, that added together give a triangular number (2850 = T₇₅).

The spelling of 2181669 in words is "two million, one hundred eighty-one thousand, six hundred sixty-nine".