1980021 has 8 divisors (see below), whose sum is σ = 2701600. Its totient is φ = 1289232.

The previous prime is 1980019. The next prime is 1980023. The reversal of 1980021 is 1200891.

It is an interprime number because it is at equal distance from previous prime (1980019) and next prime (1980023).

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

It is not a de Polignac number, because 1980021 - 2¹ = 1980019 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 1980021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1980023) 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, 7546 + ... + 7803.

It is an arithmetic number, because the mean of its divisors is an integer number (337700).

2^1980021 is an apocalyptic number.

It is an amenable number.

1980021 is a deficient number, since it is larger than the sum of its proper divisors (721579).

1980021 is a wasteful number, since it uses less digits than its factorization.

1980021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15395.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1980021 is about 1407.1321899523. The cubic root of 1980021 is about 125.5711674997.

The spelling of 1980021 in words is "one million, nine hundred eighty thousand, twenty-one".