78642591552 has 504 divisors, whose sum is σ = 280785173760. Its totient is φ = 21737963520.

The previous prime is 78642591551. The next prime is 78642591659. The reversal of 78642591552 is 25519524687.

78642591552 is a `hidden beast` number, since 7 + 8 + 6 + 42 + 591 + 5 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78642591551) 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 71 ways as a sum of consecutive naturals, for example, 23621824 + ... + 23625152.

It is an arithmetic number, because the mean of its divisors is an integer number (557113440).

Almost surely, 2^78642591552 is an apocalyptic number.

78642591552 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78642591552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140392586880).

78642591552 is an abundant number, since it is smaller than the sum of its proper divisors (202142582208).

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

78642591552 is a wasteful number, since it uses less digits than its factorization.

78642591552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3401 (or 3372 counting only the distinct ones).

The product of its digits is 6048000, while the sum is 54.

The spelling of 78642591552 in words is "seventy-eight billion, six hundred forty-two million, five hundred ninety-one thousand, five hundred fifty-two".