642151 has 2 divisors, whose sum is σ = 642152. Its totient is φ = 642150.

The previous prime is 642149. The next prime is 642157. The reversal of 642151 is 151246.

642151 is nontrivially palindromic in base 3.

642151 is an esthetic number in base 3, because in such base its adjacent digits differ by 1.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642151 - 2¹ = 642149 is a prime.

Together with 642149, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321075 + 321076.

It is an arithmetic number, because the mean of its divisors is an integer number (321076).

2⁶⁴²¹⁵¹ is an apocalyptic number.

642151 is a deficient number, since it is larger than the sum of its proper divisors (1).

642151 is an equidigital number, since it uses as much as digits as its factorization.

642151 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 642151 is about 801.3432473042. The cubic root of 642151 is about 86.2738252461.

Adding to 642151 its reverse (151246), we get a palindrome (793397).

The spelling of 642151 in words is "six hundred forty-two thousand, one hundred fifty-one".