420731 has 2 divisors, whose sum is σ = 420732. Its totient is φ = 420730.

The previous prime is 420691. The next prime is 420737. The reversal of 420731 is 137024.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420731 is a prime.

It is a super-2 number, since 2×420731² = 354029148722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (420737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210365 + 210366.

It is an arithmetic number, because the mean of its divisors is an integer number (210366).

2⁴²⁰⁷³¹ is an apocalyptic number.

420731 is a deficient number, since it is larger than the sum of its proper divisors (1).

420731 is an equidigital number, since it uses as much as digits as its factorization.

420731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 420731 is about 648.6378034003. The cubic root of 420731 is about 74.9321460371.

Adding to 420731 its reverse (137024), we get a palindrome (557755).

The spelling of 420731 in words is "four hundred twenty thousand, seven hundred thirty-one".