642220817803 has 2 divisors, whose sum is σ = 642220817804. Its totient is φ = 642220817802.

The previous prime is 642220817779. The next prime is 642220817807. The reversal of 642220817803 is 308718022246.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642220817803 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642220817803.

It is not a weakly prime, because it can be changed into another prime (642220817807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321110408901 + 321110408902.

It is an arithmetic number, because the mean of its divisors is an integer number (321110408902).

Almost surely, 2^642220817803 is an apocalyptic number.

642220817803 is a deficient number, since it is larger than the sum of its proper divisors (1).

642220817803 is an equidigital number, since it uses as much as digits as its factorization.

642220817803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 258048, while the sum is 43.

The spelling of 642220817803 in words is "six hundred forty-two billion, two hundred twenty million, eight hundred seventeen thousand, eight hundred three".