421560221 has 2 divisors, whose sum is σ = 421560222. Its totient is φ = 421560220.

The previous prime is 421560199. The next prime is 421560247. The reversal of 421560221 is 122065124.

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., 225420196 + 196140025 = 15014^2 + 14005^2 .

It is a cyclic number.

It is not a de Polignac number, because 421560221 - 2¹⁰ = 421559197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421560521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210780110 + 210780111.

It is an arithmetic number, because the mean of its divisors is an integer number (210780111).

Almost surely, 2^421560221 is an apocalyptic number.

It is an amenable number.

421560221 is a deficient number, since it is larger than the sum of its proper divisors (1).

421560221 is an equidigital number, since it uses as much as digits as its factorization.

421560221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 421560221 is about 20531.9317405840. The cubic root of 421560221 is about 749.8134178830.

The spelling of 421560221 in words is "four hundred twenty-one million, five hundred sixty thousand, two hundred twenty-one".