63977779368 has 80 divisors (see below), whose sum is σ = 179431444500. Its totient is φ = 21298028544.

The previous prime is 63977779357. The next prime is 63977779391. The reversal of 63977779368 is 86397777936.

It can be written as a sum of positive squares in 2 ways, for example, as 58533995844 + 5443783524 = 241938^2 + 73782^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 63977779296 and 63977779305.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 434118 + ... + 562506.

Almost surely, 2^63977779368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 63977779368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89715722250).

63977779368 is an abundant number, since it is smaller than the sum of its proper divisors (115453665132).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

63977779368 is a wasteful number, since it uses less digits than its factorization.

63977779368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129176 (or 129163 counting only the distinct ones).

The product of its digits is 504094752, while the sum is 72.

The spelling of 63977779368 in words is "sixty-three billion, nine hundred seventy-seven million, seven hundred seventy-nine thousand, three hundred sixty-eight".