1815406 has 4 divisors (see below), whose sum is σ = 2723112. Its totient is φ = 907702.

The previous prime is 1815403. The next prime is 1815427. The reversal of 1815406 is 6045181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6045181 = 163 ⋅37087.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1815403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 453850 + ... + 453853.

It is an arithmetic number, because the mean of its divisors is an integer number (680778).

2^1815406 is an apocalyptic number.

1815406 is a deficient number, since it is larger than the sum of its proper divisors (907706).

1815406 is an equidigital number, since it uses as much as digits as its factorization.

1815406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907705.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1815406 is about 1347.3700308379. The cubic root of 1815406 is about 121.9901004240.

The spelling of 1815406 in words is "one million, eight hundred fifteen thousand, four hundred six".