1821918 has 24 divisors (see below), whose sum is σ = 4239432. Its totient is φ = 520464.

The previous prime is 1821913. The next prime is 1821923. The reversal of 1821918 is 8191281.

It is an interprime number because it is at equal distance from previous prime (1821913) and next prime (1821923).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2805 + ... + 3392.

It is an arithmetic number, because the mean of its divisors is an integer number (176643).

2^1821918 is an apocalyptic number.

1821918 is an abundant number, since it is smaller than the sum of its proper divisors (2417514).

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

1821918 is a wasteful number, since it uses less digits than its factorization.

1821918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6216 (or 6209 counting only the distinct ones).

The product of its digits is 1152, while the sum is 30.

The square root of 1821918 is about 1349.7844272327. The cubic root of 1821918 is about 122.1357889670.

The spelling of 1821918 in words is "one million, eight hundred twenty-one thousand, nine hundred eighteen".