646476557 has 2 divisors, whose sum is σ = 646476558. Its totient is φ = 646476556.

The previous prime is 646476553. The next prime is 646476569. The reversal of 646476557 is 755674646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 505080676 + 141395881 = 22474^2 + 11891^2 .

It is a cyclic number.

It is not a de Polignac number, because 646476557 - 2² = 646476553 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646476553) 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, 323238278 + 323238279.

It is an arithmetic number, because the mean of its divisors is an integer number (323238279).

Almost surely, 2^646476557 is an apocalyptic number.

It is an amenable number.

646476557 is a deficient number, since it is larger than the sum of its proper divisors (1).

646476557 is an equidigital number, since it uses as much as digits as its factorization.

646476557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 50.

The square root of 646476557 is about 25425.9032681240. The cubic root of 646476557 is about 864.6710665302.

The spelling of 646476557 in words is "six hundred forty-six million, four hundred seventy-six thousand, five hundred fifty-seven".