1651986 has 36 divisors (see below), whose sum is σ = 4165902. Its totient is φ = 471744.

The previous prime is 1651981. The next prime is 1652011. The reversal of 1651986 is 6891561.

It can be written as a sum of positive squares in only one way, i.e., 1640961 + 11025 = 1281^2 + 105^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1651986.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1651981) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 55 + ... + 1818.

2^1651986 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1651986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2082951).

1651986 is an abundant number, since it is smaller than the sum of its proper divisors (2513916).

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

1651986 is a wasteful number, since it uses less digits than its factorization.

1651986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1895 (or 1885 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 1651986 is about 1285.2960748403. The cubic root of 1651986 is about 118.2139659003.

The spelling of 1651986 in words is "one million, six hundred fifty-one thousand, nine hundred eighty-six".