63431378521 has 24 divisors (see below), whose sum is σ = 74326165056. Its totient is φ = 53974095840.

The previous prime is 63431378399. The next prime is 63431378599. The reversal of 63431378521 is 12587313436.

It is not a de Polignac number, because 63431378521 - 2¹³ = 63431370329 is a prime.

It is a super-3 number, since 3×63431378521³ (a number of 33 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63431370521) 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 23 ways as a sum of consecutive naturals, for example, 4500916 + ... + 4514986.

It is an arithmetic number, because the mean of its divisors is an integer number (3096923544).

Almost surely, 2^63431378521 is an apocalyptic number.

It is an amenable number.

63431378521 is a deficient number, since it is larger than the sum of its proper divisors (10894786535).

63431378521 is a wasteful number, since it uses less digits than its factorization.

63431378521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14749 (or 14742 counting only the distinct ones).

The product of its digits is 362880, while the sum is 43.

The spelling of 63431378521 in words is "sixty-three billion, four hundred thirty-one million, three hundred seventy-eight thousand, five hundred twenty-one".