642421236623 has 2 divisors, whose sum is σ = 642421236624. Its totient is φ = 642421236622.

The previous prime is 642421236581. The next prime is 642421236641. The reversal of 642421236623 is 326632124246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642421236623 - 2⁸ = 642421236367 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642421235623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321210618311 + 321210618312.

It is an arithmetic number, because the mean of its divisors is an integer number (321210618312).

Almost surely, 2^642421236623 is an apocalyptic number.

642421236623 is a deficient number, since it is larger than the sum of its proper divisors (1).

642421236623 is an equidigital number, since it uses as much as digits as its factorization.

642421236623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 497664, while the sum is 41.

The spelling of 642421236623 in words is "six hundred forty-two billion, four hundred twenty-one million, two hundred thirty-six thousand, six hundred twenty-three".