630688517281 has 27 divisors (see below), whose sum is σ = 657503554617. Its totient is φ = 604958559840.

The previous prime is 630688517209. The next prime is 630688517293. The reversal of 630688517281 is 182715886036.

The square root of 630688517281 is 794159.

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

It can be written as a sum of positive squares in 4 ways, for example, as 424041904225 + 206646613056 = 651185^2 + 454584^2 .

It is not a de Polignac number, because 630688517281 - 2⁹ = 630688516769 is a prime.

It is a super-2 number, since 2×630688517281² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (630688617281) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2276853715 + ... + 2276853991.

Almost surely, 2^630688517281 is an apocalyptic number.

630688517281 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

630688517281 is the 794159-th square number.

630688517281 is the 397080-th centered octagonal number.

It is an amenable number.

630688517281 is a deficient number, since it is larger than the sum of its proper divisors (26815037336).

630688517281 is an frugal number, since it uses more digits than its factorization.

630688517281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 630688517281 in words is "six hundred thirty billion, six hundred eighty-eight million, five hundred seventeen thousand, two hundred eighty-one".