6378435981 has 24 divisors (see below), whose sum is σ = 9294199200. Its totient is φ = 4215026400.

The previous prime is 6378435977. The next prime is 6378435991. The reversal of 6378435981 is 1895348736.

6378435981 is a `hidden beast` number, since 6 + 3 + 7 + 8 + 43 + 598 + 1 = 666.

It is not a de Polignac number, because 6378435981 - 2² = 6378435977 is a prime.

It is a super-2 number, since 2×6378435981² = 81368891127430864722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6378435911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1248370 + ... + 1253468.

It is an arithmetic number, because the mean of its divisors is an integer number (387258300).

Almost surely, 2^6378435981 is an apocalyptic number.

It is an amenable number.

6378435981 is a deficient number, since it is larger than the sum of its proper divisors (2915763219).

6378435981 is a wasteful number, since it uses less digits than its factorization.

6378435981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6297 (or 6294 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The square root of 6378435981 is about 79865.1111625095. Note that the first 4 decimals coincide. The cubic root of 6378435981 is about 1854.5479514482.

The spelling of 6378435981 in words is "six billion, three hundred seventy-eight million, four hundred thirty-five thousand, nine hundred eighty-one".