63878077981 has 4 divisors (see below), whose sum is σ = 64475069472. Its totient is φ = 63281086492.

The previous prime is 63878077891. The next prime is 63878078003. The reversal of 63878077981 is 18977087836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 63878077981 - 2¹⁵ = 63878045213 is a prime.

It is a super-2 number, since 2×63878077981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63878071981) 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 3 ways as a sum of consecutive naturals, for example, 298495585 + ... + 298495798.

It is an arithmetic number, because the mean of its divisors is an integer number (16118767368).

Almost surely, 2^63878077981 is an apocalyptic number.

It is an amenable number.

63878077981 is a deficient number, since it is larger than the sum of its proper divisors (596991491).

63878077981 is a wasteful number, since it uses less digits than its factorization.

63878077981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596991490.

The product of its (nonzero) digits is 28449792, while the sum is 64.

The spelling of 63878077981 in words is "sixty-three billion, eight hundred seventy-eight million, seventy-seven thousand, nine hundred eighty-one".