642243331 has 2 divisors, whose sum is σ = 642243332. Its totient is φ = 642243330.

The previous prime is 642243271. The next prime is 642243359. The reversal of 642243331 is 133342246.

642243331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (642243359) can be obtained adding 642243331 to its sum of digits (28).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642243331 - 2²¹ = 640146179 is a prime.

It is a super-2 number, since 2×642243331² = 824952992427951122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642243331.

It is not a weakly prime, because it can be changed into another prime (642243361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321121665 + 321121666.

It is an arithmetic number, because the mean of its divisors is an integer number (321121666).

Almost surely, 2^642243331 is an apocalyptic number.

642243331 is a deficient number, since it is larger than the sum of its proper divisors (1).

642243331 is an equidigital number, since it uses as much as digits as its factorization.

642243331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 28.

The square root of 642243331 is about 25342.5202180052. The cubic root of 642243331 is about 862.7795997805.

Adding to 642243331 its reverse (133342246), we get a palindrome (775585577).

The spelling of 642243331 in words is "six hundred forty-two million, two hundred forty-three thousand, three hundred thirty-one".