78391724396544 has 1560 divisors, whose sum is σ = 267968187558720. Its totient is φ = 22779177467904.

The previous prime is 78391724396477. The next prime is 78391724396561. The reversal of 78391724396544 is 44569342719387.

78391724396544 is a `hidden beast` number, since 7 + 8 + 3 + 9 + 1 + 72 + 4 + 3 + 9 + 6 + 544 = 666.

It is a super-2 number, since 2×78391724396544² (a number of 29 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 114775584427 + ... + 114775585109.

Almost surely, 2^{78391724396544} 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 78391724396544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133984093779360).

78391724396544 is an abundant number, since it is smaller than the sum of its proper divisors (189576463162176).

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

78391724396544 is a wasteful number, since it uses less digits than its factorization.

78391724396544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 857 (or 813 counting only the distinct ones).

The product of its digits is 1097349120, while the sum is 72.

The spelling of 78391724396544 in words is "seventy-eight trillion, three hundred ninety-one billion, seven hundred twenty-four million, three hundred ninety-six thousand, five hundred forty-four".