1821087 has 6 divisors (see below), whose sum is σ = 2630472. Its totient is φ = 1214052.

The previous prime is 1821067. The next prime is 1821101. The reversal of 1821087 is 7801281.

It is a de Polignac number, because none of the positive numbers 2^k-1821087 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1821087.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821037) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101163 + ... + 101180.

It is an arithmetic number, because the mean of its divisors is an integer number (438412).

2^1821087 is an apocalyptic number.

1821087 is a deficient number, since it is larger than the sum of its proper divisors (809385).

1821087 is a wasteful number, since it uses less digits than its factorization.

1821087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202349 (or 202346 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 1821087 is about 1349.4765651911. The cubic root of 1821087 is about 122.1172169135.

The spelling of 1821087 in words is "one million, eight hundred twenty-one thousand, eighty-seven".