12345671557 has 2 divisors, whose sum is σ = 12345671558. Its totient is φ = 12345671556.

The previous prime is 12345671551. The next prime is 12345671587. The reversal of 12345671557 is 75517654321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12071636641 + 274034916 = 109871^2 + 16554^2 .

It is an emirp because it is prime and its reverse (75517654321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12345671557 - 2³ = 12345671549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12345671551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6172835778 + 6172835779.

It is an arithmetic number, because the mean of its divisors is an integer number (6172835779).

Almost surely, 2^12345671557 is an apocalyptic number.

It is an amenable number.

12345671557 is a deficient number, since it is larger than the sum of its proper divisors (1).

12345671557 is an equidigital number, since it uses as much as digits as its factorization.

12345671557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 882000, while the sum is 46.

The spelling of 12345671557 in words is "twelve billion, three hundred forty-five million, six hundred seventy-one thousand, five hundred fifty-seven".