2181810 has 16 divisors (see below), whose sum is σ = 5236416. Its totient is φ = 581808.

The previous prime is 2181737. The next prime is 2181833. The reversal of 2181810 is 181812.

2181810 = T₃₃₀ + T₃₃₁ + ... + T₃₆₅.

It is a super-2 number, since 2×2181810² = 9520589752200, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36334 + ... + 36393.

It is an arithmetic number, because the mean of its divisors is an integer number (327276).

2^2181810 is an apocalyptic number.

2181810 is an abundant number, since it is smaller than the sum of its proper divisors (3054606).

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

2181810 is a wasteful number, since it uses less digits than its factorization.

2181810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72737.

The product of its (nonzero) digits is 128, while the sum is 21.

The square root of 2181810 is about 1477.0951221908. The cubic root of 2181810 is about 129.6997013246.

The spelling of 2181810 in words is "two million, one hundred eighty-one thousand, eight hundred ten".