642224789 has 2 divisors, whose sum is σ = 642224790. Its totient is φ = 642224788.

The previous prime is 642224783. The next prime is 642224809. The reversal of 642224789 is 987422246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 485849764 + 156375025 = 22042^2 + 12505^2 .

It is a cyclic number.

It is not a de Polignac number, because 642224789 - 2⁴ = 642224773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642224783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321112394 + 321112395.

It is an arithmetic number, because the mean of its divisors is an integer number (321112395).

Almost surely, 2^642224789 is an apocalyptic number.

It is an amenable number.

642224789 is a deficient number, since it is larger than the sum of its proper divisors (1).

642224789 is an equidigital number, since it uses as much as digits as its factorization.

642224789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 44.

The square root of 642224789 is about 25342.1543875023. The cubic root of 642224789 is about 862.7712966901.

The spelling of 642224789 in words is "six hundred forty-two million, two hundred twenty-four thousand, seven hundred eighty-nine".