642629161 has 2 divisors, whose sum is σ = 642629162. Its totient is φ = 642629160.

The previous prime is 642629159. The next prime is 642629173. The reversal of 642629161 is 161926246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 358875136 + 283754025 = 18944^2 + 16845^2 .

It is a cyclic number.

It is not a de Polignac number, because 642629161 - 2¹ = 642629159 is a prime.

It is a super-3 number, since 3×642629161³ (a number of 27 digits) contains 333 as substring.

Together with 642629159, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 642629161.

It is not a weakly prime, because it can be changed into another prime (642624161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321314580 + 321314581.

It is an arithmetic number, because the mean of its divisors is an integer number (321314581).

Almost surely, 2^642629161 is an apocalyptic number.

It is an amenable number.

642629161 is a deficient number, since it is larger than the sum of its proper divisors (1).

642629161 is an equidigital number, since it uses as much as digits as its factorization.

642629161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 642629161 is about 25350.1313803302. The cubic root of 642629161 is about 862.9523378474.

The spelling of 642629161 in words is "six hundred forty-two million, six hundred twenty-nine thousand, one hundred sixty-one".