2051989 has 4 divisors (see below), whose sum is σ = 2058156. Its totient is φ = 2045824.

The previous prime is 2051969. The next prime is 2051999. The reversal of 2051989 is 9891502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1134225 + 917764 = 1065^2 + 958^2 .

It is a cyclic number.

It is not a de Polignac number, because 2051989 - 2⁹ = 2051477 is a prime.

It is a super-2 number, since 2×2051989² = 8421317712242, which contains 22 as substring.

It is a Duffinian number.

2051989 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2554 + ... + 3259.

It is an arithmetic number, because the mean of its divisors is an integer number (514539).

2^2051989 is an apocalyptic number.

It is an amenable number.

2051989 is a deficient number, since it is larger than the sum of its proper divisors (6167).

2051989 is an equidigital number, since it uses as much as digits as its factorization.

2051989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6166.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 2051989 is about 1432.4765268583. The cubic root of 2051989 is about 127.0744804607.

The spelling of 2051989 in words is "two million, fifty-one thousand, nine hundred eighty-nine".