6637120740121 has 3 divisors (see below), whose sum is σ = 6637123316383. Its totient is φ = 6637118163860.

The previous prime is 6637120740113. The next prime is 6637120740137. The reversal of 6637120740121 is 1210470217366.

The square root of 6637120740121 is 2576261.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 206534800521 + 6430585939600 = 454461^2 + 2535860^2 .

It is not a de Polignac number, because 6637120740121 - 2³ = 6637120740113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6637120740181) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1288131 + ... + 3864391.

Almost surely, 2^{6637120740121} is an apocalyptic number.

6637120740121 is the 2576261-st square number.

6637120740121 is the 1288131-st centered octagonal number.

It is an amenable number.

6637120740121 is a deficient number, since it is larger than the sum of its proper divisors (2576262).

6637120740121 is an frugal number, since it uses more digits than its factorization.

6637120740121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5152522 (or 2576261 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 40.

Adding to 6637120740121 its reverse (1210470217366), we get a palindrome (7847590957487).

The spelling of 6637120740121 in words is "six trillion, six hundred thirty-seven billion, one hundred twenty million, seven hundred forty thousand, one hundred twenty-one".