421242431 has 2 divisors, whose sum is σ = 421242432. Its totient is φ = 421242430.

The previous prime is 421242403. The next prime is 421242443. The reversal of 421242431 is 134242124.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421242431 is a prime.

It is a super-2 number, since 2×421242431² = 354890371349579522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 421242397 and 421242406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421242131) 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, 210621215 + 210621216.

It is an arithmetic number, because the mean of its divisors is an integer number (210621216).

Almost surely, 2^421242431 is an apocalyptic number.

421242431 is a deficient number, since it is larger than the sum of its proper divisors (1).

421242431 is an equidigital number, since it uses as much as digits as its factorization.

421242431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 23.

The square root of 421242431 is about 20524.1913604410. The cubic root of 421242431 is about 749.6249567843.

Adding to 421242431 its reverse (134242124), we get a palindrome (555484555).

The spelling of 421242431 in words is "four hundred twenty-one million, two hundred forty-two thousand, four hundred thirty-one".