78261513984 has 144 divisors (see below), whose sum is σ = 239414128800. Its totient is φ = 25187549184.

The previous prime is 78261513971. The next prime is 78261513991. The reversal of 78261513984 is 48931516287.

78261513984 is a `hidden beast` number, since 7 + 8 + 2 + 615 + 13 + 9 + 8 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×78261513984² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 78261513984.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5232 + ... + 395664.

Almost surely, 2^78261513984 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 78261513984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119707064400).

78261513984 is an abundant number, since it is smaller than the sum of its proper divisors (161152614816).

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

78261513984 is a wasteful number, since it uses less digits than its factorization.

78261513984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390487 (or 390467 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The spelling of 78261513984 in words is "seventy-eight billion, two hundred sixty-one million, five hundred thirteen thousand, nine hundred eighty-four".