423813721 has 2 divisors, whose sum is σ = 423813722. Its totient is φ = 423813720.

The previous prime is 423813713. The next prime is 423813727. The reversal of 423813721 is 127318324.

It is the 8405-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242238096 + 181575625 = 15564^2 + 13475^2 .

It is a cyclic number.

It is not a de Polignac number, because 423813721 - 2³ = 423813713 is a prime.

It is equal to p_22536625 and since 423813721 and 22536625 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (423813727) 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, 211906860 + 211906861.

It is an arithmetic number, because the mean of its divisors is an integer number (211906861).

Almost surely, 2^423813721 is an apocalyptic number.

It is an amenable number.

423813721 is a deficient number, since it is larger than the sum of its proper divisors (1).

423813721 is an equidigital number, since it uses as much as digits as its factorization.

423813721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 31.

The square root of 423813721 is about 20586.7365310775. The cubic root of 423813721 is about 751.1471163081.

The spelling of 423813721 in words is "four hundred twenty-three million, eight hundred thirteen thousand, seven hundred twenty-one".