1861986 has 32 divisors (see below), whose sum is σ = 4359168. Its totient is φ = 519120.

The previous prime is 1861973. The next prime is 1861991. The reversal of 1861986 is 6891681.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1291 + ... + 2321.

It is an arithmetic number, because the mean of its divisors is an integer number (136224).

2^1861986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1861986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2179584).

1861986 is an abundant number, since it is smaller than the sum of its proper divisors (2497182).

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

1861986 is a wasteful number, since it uses less digits than its factorization.

1861986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086.

The product of its digits is 20736, while the sum is 39.

The square root of 1861986 is about 1364.5460783719. The cubic root of 1861986 is about 123.0246496966.

The spelling of 1861986 in words is "one million, eight hundred sixty-one thousand, nine hundred eighty-six".