1864021 has 4 divisors (see below), whose sum is σ = 1871532. Its totient is φ = 1856512.

The previous prime is 1864003. The next prime is 1864039. The reversal of 1864021 is 1204681.

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

It is an interprime number because it is at equal distance from previous prime (1864003) and next prime (1864039).

It can be written as a sum of positive squares in 2 ways, for example, as 1661521 + 202500 = 1289^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 1864021 - 2⁷ = 1863893 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1863983 and 1864001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1864001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3370 + ... + 3883.

It is an arithmetic number, because the mean of its divisors is an integer number (467883).

2^1864021 is an apocalyptic number.

It is an amenable number.

1864021 is a deficient number, since it is larger than the sum of its proper divisors (7511).

1864021 is an equidigital number, since it uses as much as digits as its factorization.

1864021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7510.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 1864021 is about 1365.2915439568. The cubic root of 1864021 is about 123.0694520405.

The spelling of 1864021 in words is "one million, eight hundred sixty-four thousand, twenty-one".