421604081 has 2 divisors, whose sum is σ = 421604082. Its totient is φ = 421604080.

The previous prime is 421604077. The next prime is 421604083. The reversal of 421604081 is 180406124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 407232400 + 14371681 = 20180^2 + 3791^2 .

It is a cyclic number.

It is not a de Polignac number, because 421604081 - 2² = 421604077 is a prime.

It is a super-2 number, since 2×421604081² = 355500002231709122, which contains 22 as substring.

Together with 421604083, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421604081.

It is not a weakly prime, because it can be changed into another prime (421604083) 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, 210802040 + 210802041.

It is an arithmetic number, because the mean of its divisors is an integer number (210802041).

Almost surely, 2^421604081 is an apocalyptic number.

It is an amenable number.

421604081 is a deficient number, since it is larger than the sum of its proper divisors (1).

421604081 is an equidigital number, since it uses as much as digits as its factorization.

421604081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 421604081 is about 20532.9998051916. Note that the first 3 decimals coincide. The cubic root of 421604081 is about 749.8394210291.

The spelling of 421604081 in words is "four hundred twenty-one million, six hundred four thousand, eighty-one".