1980857 has 8 divisors (see below), whose sum is σ = 2118600. Its totient is φ = 1845504.

The previous prime is 1980821. The next prime is 1980859. The reversal of 1980857 is 7580891.

It can be written as a sum of positive squares in 4 ways, for example, as 678976 + 1301881 = 824^2 + 1141^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1980857 - 2¹² = 1976761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1980857.

It is not an unprimeable number, because it can be changed into a prime (1980859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1319 + ... + 2387.

It is an arithmetic number, because the mean of its divisors is an integer number (264825).

2^1980857 is an apocalyptic number.

1980857 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1980857 is a deficient number, since it is larger than the sum of its proper divisors (137743).

1980857 is a wasteful number, since it uses less digits than its factorization.

1980857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1195.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 1980857 is about 1407.4292166926. The cubic root of 1980857 is about 125.5888378047.

The spelling of 1980857 in words is "one million, nine hundred eighty thousand, eight hundred fifty-seven".