6442878961 has 2 divisors, whose sum is σ = 6442878962. Its totient is φ = 6442878960.

The previous prime is 6442878941. The next prime is 6442878973. The reversal of 6442878961 is 1698782446.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5592048400 + 850830561 = 74780^2 + 29169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6442878961 is a prime.

It is not a weakly prime, because it can be changed into another prime (6442878941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3221439480 + 3221439481.

It is an arithmetic number, because the mean of its divisors is an integer number (3221439481).

Almost surely, 2^6442878961 is an apocalyptic number.

It is an amenable number.

6442878961 is a deficient number, since it is larger than the sum of its proper divisors (1).

6442878961 is an equidigital number, since it uses as much as digits as its factorization.

6442878961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4644864, while the sum is 55.

The square root of 6442878961 is about 80267.5461254423. The cubic root of 6442878961 is about 1860.7726932759.

The spelling of 6442878961 in words is "six billion, four hundred forty-two million, eight hundred seventy-eight thousand, nine hundred sixty-one".