2131818 has 32 divisors (see below), whose sum is σ = 4647552. Its totient is φ = 648000.

The previous prime is 2131813. The next prime is 2131823. The reversal of 2131818 is 8181312.

It is an interprime number because it is at equal distance from previous prime (2131813) and next prime (2131823).

It is not an unprimeable number, because it can be changed into a prime (2131813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11688 + ... + 11868.

It is an arithmetic number, because the mean of its divisors is an integer number (145236).

2^2131818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2131818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2323776).

2131818 is an abundant number, since it is smaller than the sum of its proper divisors (2515734).

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

2131818 is a wasteful number, since it uses less digits than its factorization.

2131818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350.

The product of its digits is 384, while the sum is 24.

The square root of 2131818 is about 1460.0746556255. The cubic root of 2131818 is about 128.7014307643.

The spelling of 2131818 in words is "two million, one hundred thirty-one thousand, eight hundred eighteen".