642040237 has 2 divisors, whose sum is σ = 642040238. Its totient is φ = 642040236.

The previous prime is 642040219. The next prime is 642040247. The reversal of 642040237 is 732040246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 420209001 + 221831236 = 20499^2 + 14894^2 .

It is a cyclic number.

It is not a de Polignac number, because 642040237 - 2¹⁵ = 642007469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642040247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321020118 + 321020119.

It is an arithmetic number, because the mean of its divisors is an integer number (321020119).

Almost surely, 2^642040237 is an apocalyptic number.

It is an amenable number.

642040237 is a deficient number, since it is larger than the sum of its proper divisors (1).

642040237 is an equidigital number, since it uses as much as digits as its factorization.

642040237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 28.

The square root of 642040237 is about 25338.5129200591. The cubic root of 642040237 is about 862.6886457630.

Subtracting 642040237 from its reverse (732040246), we obtain a palindrome (90000009).

The spelling of 642040237 in words is "six hundred forty-two million, forty thousand, two hundred thirty-seven".