421504621 has 2 divisors, whose sum is σ = 421504622. Its totient is φ = 421504620.

The previous prime is 421504597. The next prime is 421504679. The reversal of 421504621 is 126405124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 364275396 + 57229225 = 19086^2 + 7565^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421504621 is a prime.

It is a super-2 number, since 2×421504621² = 355332291048707282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421504121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210752310 + 210752311.

It is an arithmetic number, because the mean of its divisors is an integer number (210752311).

Almost surely, 2^421504621 is an apocalyptic number.

It is an amenable number.

421504621 is a deficient number, since it is larger than the sum of its proper divisors (1).

421504621 is an equidigital number, since it uses as much as digits as its factorization.

421504621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 421504621 is about 20530.5777074100. The cubic root of 421504621 is about 749.7804518859.

Adding to 421504621 its reverse (126405124), we get a palindrome (547909745).

The spelling of 421504621 in words is "four hundred twenty-one million, five hundred four thousand, six hundred twenty-one".