421667839 has 2 divisors, whose sum is σ = 421667840. Its totient is φ = 421667838.

The previous prime is 421667837. The next prime is 421667861. The reversal of 421667839 is 938766124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 421667839 - 2¹ = 421667837 is a prime.

Together with 421667837, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421667833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210833919 + 210833920.

It is an arithmetic number, because the mean of its divisors is an integer number (210833920).

Almost surely, 2^421667839 is an apocalyptic number.

421667839 is a deficient number, since it is larger than the sum of its proper divisors (1).

421667839 is an equidigital number, since it uses as much as digits as its factorization.

421667839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 46.

The square root of 421667839 is about 20534.5523204184. The cubic root of 421667839 is about 749.8772178264.

It can be divided in two parts, 42166 and 7839, that added together give a palindrome (50005).

The spelling of 421667839 in words is "four hundred twenty-one million, six hundred sixty-seven thousand, eight hundred thirty-nine".