631978890841 has 27 divisors (see below), whose sum is σ = 679521290493. Its totient is φ = 587642563200.

The previous prime is 631978890827. The next prime is 631978890971. The reversal of 631978890841 is 148098879136.

The square root of 631978890841 is 794971.

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 376351575625 + 255627315216 = 613475^2 + 505596^2 .

It is not a de Polignac number, because 631978890841 - 2⁷ = 631978890713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631978893841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1364964976 + ... + 1364965438.

Almost surely, 2^631978890841 is an apocalyptic number.

631978890841 is the 794971-st square number.

631978890841 is the 397486-th centered octagonal number.

It is an amenable number.

631978890841 is a deficient number, since it is larger than the sum of its proper divisors (47542399652).

631978890841 is an frugal number, since it uses more digits than its factorization.

631978890841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162 (or 581 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 64.

Multiplying 631978890841 by its sum of digits (64), we get a square (40446649013824 = 6359768²).

The spelling of 631978890841 in words is "six hundred thirty-one billion, nine hundred seventy-eight million, eight hundred ninety thousand, eight hundred forty-one".