4638987976561 has 9 divisors (see below), whose sum is σ = 4658086471179. Its totient is φ = 4619967495000.

The previous prime is 4638987976463. The next prime is 4638987976583. The reversal of 4638987976561 is 1656797898364.

The square root of 4638987976561 is 2153831.

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., 1081160161 + 4637906816400 = 32881^2 + 2153580^2 .

It is not a de Polignac number, because 4638987976561 - 2¹¹ = 4638987974513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4638987976261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 540607291 + ... + 540615871.

Almost surely, 2^{4638987976561} is an apocalyptic number.

4638987976561 is the 2153831-st square number.

4638987976561 is the 1076916-th centered octagonal number.

It is an amenable number.

4638987976561 is a deficient number, since it is larger than the sum of its proper divisors (19098494618).

4638987976561 is an frugal number, since it uses more digits than its factorization.

4638987976561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17664 (or 8832 counting only the distinct ones).

The product of its digits is 3292047360, while the sum is 79.

The spelling of 4638987976561 in words is "four trillion, six hundred thirty-eight billion, nine hundred eighty-seven million, nine hundred seventy-six thousand, five hundred sixty-one".