6420002161 has 2 divisors, whose sum is σ = 6420002162. Its totient is φ = 6420002160.

The previous prime is 6420002159. The next prime is 6420002189. The reversal of 6420002161 is 1612000246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3485721600 + 2934280561 = 59040^2 + 54169^2 .

It is a cyclic number.

It is not a de Polignac number, because 6420002161 - 2¹ = 6420002159 is a prime.

Together with 6420002159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6420002101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3210001080 + 3210001081.

It is an arithmetic number, because the mean of its divisors is an integer number (3210001081).

Almost surely, 2^6420002161 is an apocalyptic number.

It is an amenable number.

6420002161 is a deficient number, since it is larger than the sum of its proper divisors (1).

6420002161 is an equidigital number, since it uses as much as digits as its factorization.

6420002161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 6420002161 is about 80124.9159812352. The cubic root of 6420002161 is about 1858.5677262382.

The spelling of 6420002161 in words is "six billion, four hundred twenty million, two thousand, one hundred sixty-one".