8213439557 has 2 divisors, whose sum is σ = 8213439558. Its totient is φ = 8213439556.

The previous prime is 8213439511. The next prime is 8213439599. The reversal of 8213439557 is 7559343128.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4126906081 + 4086533476 = 64241^2 + 63926^2 .

It is a cyclic number.

It is not a de Polignac number, because 8213439557 - 2¹⁶ = 8213374021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8213436557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4106719778 + 4106719779.

It is an arithmetic number, because the mean of its divisors is an integer number (4106719779).

Almost surely, 2^8213439557 is an apocalyptic number.

It is an amenable number.

8213439557 is a deficient number, since it is larger than the sum of its proper divisors (1).

8213439557 is an equidigital number, since it uses as much as digits as its factorization.

8213439557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 47.

The square root of 8213439557 is about 90628.0285397404. The cubic root of 8213439557 is about 2017.6307513531.

The spelling of 8213439557 in words is "eight billion, two hundred thirteen million, four hundred thirty-nine thousand, five hundred fifty-seven".