1861636 has 24 divisors (see below), whose sum is σ = 3943296. Its totient is φ = 750720.

The previous prime is 1861631. The next prime is 1861637. The reversal of 1861636 is 6361681.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1861598 and 1861607.

It is not an unprimeable number, because it can be changed into a prime (1861631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1480 + ... + 2431.

It is an arithmetic number, because the mean of its divisors is an integer number (164304).

2^1861636 is an apocalyptic number.

It is an amenable number.

1861636 is an abundant number, since it is smaller than the sum of its proper divisors (2081660).

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

1861636 is a wasteful number, since it uses less digits than its factorization.

1861636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3939 (or 3937 counting only the distinct ones).

The product of its digits is 5184, while the sum is 31.

The square root of 1861636 is about 1364.4178245684. The cubic root of 1861636 is about 123.0169408442.

The spelling of 1861636 in words is "one million, eight hundred sixty-one thousand, six hundred thirty-six".