642646306129 has 2 divisors, whose sum is σ = 642646306130. Its totient is φ = 642646306128.

The previous prime is 642646306121. The next prime is 642646306213. The reversal of 642646306129 is 921603646246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 620907752529 + 21738553600 = 787977^2 + 147440^2 .

It is a cyclic number.

It is not a de Polignac number, because 642646306129 - 2³ = 642646306121 is a prime.

It is not a weakly prime, because it can be changed into another prime (642646306121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321323153064 + 321323153065.

It is an arithmetic number, because the mean of its divisors is an integer number (321323153065).

Almost surely, 2^642646306129 is an apocalyptic number.

It is an amenable number.

642646306129 is a deficient number, since it is larger than the sum of its proper divisors (1).

642646306129 is an equidigital number, since it uses as much as digits as its factorization.

642646306129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2239488, while the sum is 49.

The spelling of 642646306129 in words is "six hundred forty-two billion, six hundred forty-six million, three hundred six thousand, one hundred twenty-nine".