126642557 has 2 divisors, whose sum is σ = 126642558. Its totient is φ = 126642556.

The previous prime is 126642553. The next prime is 126642569. The reversal of 126642557 is 755246621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79459396 + 47183161 = 8914^2 + 6869^2 .

It is an emirp because it is prime and its reverse (755246621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 126642557 - 2² = 126642553 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 126642557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (126642553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63321278 + 63321279.

It is an arithmetic number, because the mean of its divisors is an integer number (63321279).

Almost surely, 2^126642557 is an apocalyptic number.

It is an amenable number.

126642557 is a deficient number, since it is larger than the sum of its proper divisors (1).

126642557 is an equidigital number, since it uses as much as digits as its factorization.

126642557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 38.

The square root of 126642557 is about 11253.5575264003. The cubic root of 126642557 is about 502.1805525569.

The spelling of 126642557 in words is "one hundred twenty-six million, six hundred forty-two thousand, five hundred fifty-seven".