421487921 has 2 divisors, whose sum is σ = 421487922. Its totient is φ = 421487920.

The previous prime is 421487863. The next prime is 421487971. The reversal of 421487921 is 129784124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 355699600 + 65788321 = 18860^2 + 8111^2 .

It is a cyclic number.

It is not a de Polignac number, because 421487921 - 2¹⁴ = 421471537 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (421487971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210743960 + 210743961.

It is an arithmetic number, because the mean of its divisors is an integer number (210743961).

Almost surely, 2^421487921 is an apocalyptic number.

It is an amenable number.

421487921 is a deficient number, since it is larger than the sum of its proper divisors (1).

421487921 is an equidigital number, since it uses as much as digits as its factorization.

421487921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 38.

The square root of 421487921 is about 20530.1709929557. The cubic root of 421487921 is about 749.7705496624.

The spelling of 421487921 in words is "four hundred twenty-one million, four hundred eighty-seven thousand, nine hundred twenty-one".