2021858 has 4 divisors (see below), whose sum is σ = 3032790. Its totient is φ = 1010928.

The previous prime is 2021849. The next prime is 2021863. The reversal of 2021858 is 8581202.

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

It can be written as a sum of positive squares in only one way, i.e., 1646089 + 375769 = 1283^2 + 613^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 505463 + ... + 505466.

2^2021858 is an apocalyptic number.

2021858 is a deficient number, since it is larger than the sum of its proper divisors (1010932).

2021858 is a wasteful number, since it uses less digits than its factorization.

2021858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010931.

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 2021858 is about 1421.9205322380. The cubic root of 2021858 is about 126.4494322092.

The spelling of 2021858 in words is "two million, twenty-one thousand, eight hundred fifty-eight".