642658061 has 2 divisors, whose sum is σ = 642658062. Its totient is φ = 642658060.

The previous prime is 642658039. The next prime is 642658099. The reversal of 642658061 is 160856246.

642658061 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 (642658099) can be obtained adding 642658061 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 367297225 + 275360836 = 19165^2 + 16594^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642658061 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642658001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321329030 + 321329031.

It is an arithmetic number, because the mean of its divisors is an integer number (321329031).

Almost surely, 2^642658061 is an apocalyptic number.

It is an amenable number.

642658061 is a deficient number, since it is larger than the sum of its proper divisors (1).

642658061 is an equidigital number, since it uses as much as digits as its factorization.

642658061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 642658061 is about 25350.7013906913. The cubic root of 642658061 is about 862.9652737417.

The spelling of 642658061 in words is "six hundred forty-two million, six hundred fifty-eight thousand, sixty-one".