1858421 has 2 divisors, whose sum is σ = 1858422. Its totient is φ = 1858420.

The previous prime is 1858403. The next prime is 1858433. The reversal of 1858421 is 1248581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1234321 + 624100 = 1111^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 1858421 - 2¹⁸ = 1596277 is a prime.

It is a super-2 number, since 2×1858421² = 6907457226482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1858721) 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 as a sum of consecutive naturals, namely, 929210 + 929211.

It is an arithmetic number, because the mean of its divisors is an integer number (929211).

2^1858421 is an apocalyptic number.

It is an amenable number.

1858421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1858421 is an equidigital number, since it uses as much as digits as its factorization.

1858421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2560, while the sum is 29.

The square root of 1858421 is about 1363.2391573015. The cubic root of 1858421 is about 122.9460842864.

The spelling of 1858421 in words is "one million, eight hundred fifty-eight thousand, four hundred twenty-one".