642226873 has 2 divisors, whose sum is σ = 642226874. Its totient is φ = 642226872.

The previous prime is 642226831. The next prime is 642226889. The reversal of 642226873 is 378622246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 577537024 + 64689849 = 24032^2 + 8043^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642226873 is a prime.

It is not a weakly prime, because it can be changed into another prime (642226073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321113436 + 321113437.

It is an arithmetic number, because the mean of its divisors is an integer number (321113437).

Almost surely, 2^642226873 is an apocalyptic number.

It is an amenable number.

642226873 is a deficient number, since it is larger than the sum of its proper divisors (1).

642226873 is an equidigital number, since it uses as much as digits as its factorization.

642226873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 40.

The square root of 642226873 is about 25342.1955047308. The cubic root of 642226873 is about 862.7722299113.

The spelling of 642226873 in words is "six hundred forty-two million, two hundred twenty-six thousand, eight hundred seventy-three".