127242737521 has 9 divisors (see below), whose sum is σ = 135174332811. Its totient is φ = 119752163232.

The previous prime is 127242737519. The next prime is 127242737539. The reversal of 127242737521 is 125737242721.

The square root of 127242737521 is 356711.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 99064415025 + 28178322496 = 314745^2 + 167864^2 .

It is not a de Polignac number, because 127242737521 - 2¹ = 127242737519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127242737581) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6053596 + ... + 6074578.

Almost surely, 2^127242737521 is an apocalyptic number.

127242737521 is the 356711-st square number.

127242737521 is the 178356-th centered octagonal number.

It is an amenable number.

127242737521 is a deficient number, since it is larger than the sum of its proper divisors (7931595290).

127242737521 is an frugal number, since it uses more digits than its factorization.

127242737521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42000 (or 21000 counting only the distinct ones).

The product of its digits is 329280, while the sum is 43.

The spelling of 127242737521 in words is "one hundred twenty-seven billion, two hundred forty-two million, seven hundred thirty-seven thousand, five hundred twenty-one".