1820638 has 8 divisors (see below), whose sum is σ = 2752200. Its totient is φ = 903240.

The previous prime is 1820633. The next prime is 1820641. The reversal of 1820638 is 8360281.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3213 + ... + 3736.

It is an arithmetic number, because the mean of its divisors is an integer number (344025).

2^1820638 is an apocalyptic number.

1820638 is a deficient number, since it is larger than the sum of its proper divisors (931562).

1820638 is a wasteful number, since it uses less digits than its factorization.

1820638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7082.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 1820638 is about 1349.3101941362. The cubic root of 1820638 is about 122.1071798427.

The spelling of 1820638 in words is "one million, eight hundred twenty thousand, six hundred thirty-eight".