1812381 has 8 divisors (see below), whose sum is σ = 2424864. Its totient is φ = 1204080.

The previous prime is 1812379. The next prime is 1812383. The reversal of 1812381 is 1832181.

It is an interprime number because it is at equal distance from previous prime (1812379) and next prime (1812383).

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

It is not a de Polignac number, because 1812381 - 2¹ = 1812379 is a prime.

It is a super-2 number, since 2×1812381² = 6569449778322, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1812383) 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, 171 + ... + 1911.

It is an arithmetic number, because the mean of its divisors is an integer number (303108).

2^1812381 is an apocalyptic number.

It is an amenable number.

1812381 is a deficient number, since it is larger than the sum of its proper divisors (612483).

1812381 is a wasteful number, since it uses less digits than its factorization.

1812381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091.

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

The square root of 1812381 is about 1346.2470055677. The cubic root of 1812381 is about 121.9223056334.

The spelling of 1812381 in words is "one million, eight hundred twelve thousand, three hundred eighty-one".