1867421 has 2 divisors, whose sum is σ = 1867422. Its totient is φ = 1867420.

The previous prime is 1867373. The next prime is 1867423. The reversal of 1867421 is 1247681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1716100 + 151321 = 1310^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 1867421 - 2¹⁸ = 1605277 is a prime.

It is a super-2 number, since 2×1867421² = 6974522382482, which contains 22 as substring.

Together with 1867423, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₁₃₉₇₈₁ and since 1867421 and 139781 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1867423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 933710 + 933711.

It is an arithmetic number, because the mean of its divisors is an integer number (933711).

2^1867421 is an apocalyptic number.

It is an amenable number.

1867421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1867421 is an equidigital number, since it uses as much as digits as its factorization.

1867421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 29.

The square root of 1867421 is about 1366.5361319775. The cubic root of 1867421 is about 123.1442333839.

The spelling of 1867421 in words is "one million, eight hundred sixty-seven thousand, four hundred twenty-one".