6478889581 has 2 divisors, whose sum is σ = 6478889582. Its totient is φ = 6478889580.

The previous prime is 6478889579. The next prime is 6478889603. The reversal of 6478889581 is 1859888746.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5976681481 + 502208100 = 77309^2 + 22410^2 .

It is a cyclic number.

It is not a de Polignac number, because 6478889581 - 2¹ = 6478889579 is a prime.

It is a super-2 number, since 2×6478889581² = 83952020405580711122, which contains 22 as substring.

Together with 6478889579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6478889531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3239444790 + 3239444791.

It is an arithmetic number, because the mean of its divisors is an integer number (3239444791).

Almost surely, 2^6478889581 is an apocalyptic number.

It is an amenable number.

6478889581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6478889581 is an equidigital number, since it uses as much as digits as its factorization.

6478889581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30965760, while the sum is 64.

The square root of 6478889581 is about 80491.5497490265. The cubic root of 6478889581 is about 1864.2330058219.

The spelling of 6478889581 in words is "six billion, four hundred seventy-eight million, eight hundred eighty-nine thousand, five hundred eighty-one".