421401509 has 2 divisors, whose sum is σ = 421401510. Its totient is φ = 421401508.

The previous prime is 421401499. The next prime is 421401517. The reversal of 421401509 is 905104124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 352876225 + 68525284 = 18785^2 + 8278^2 .

It is a cyclic number.

It is not a de Polignac number, because 421401509 - 2²⁸ = 152966053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421401529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210700754 + 210700755.

It is an arithmetic number, because the mean of its divisors is an integer number (210700755).

Almost surely, 2^421401509 is an apocalyptic number.

It is an amenable number.

421401509 is a deficient number, since it is larger than the sum of its proper divisors (1).

421401509 is an equidigital number, since it uses as much as digits as its factorization.

421401509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 421401509 is about 20528.0663726519. The cubic root of 421401509 is about 749.7193077030.

The spelling of 421401509 in words is "four hundred twenty-one million, four hundred one thousand, five hundred nine".