78411921408 has 576 divisors, whose sum is σ = 251848396800. Its totient is φ = 23410114560.

The previous prime is 78411921407. The next prime is 78411921431. The reversal of 78411921408 is 80412911487.

78411921408 is a `hidden beast` number, since 7 + 8 + 411 + 92 + 140 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×78411921408² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78411921407) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 617416641 + ... + 617416767.

It is an arithmetic number, because the mean of its divisors is an integer number (437236800).

Almost surely, 2^78411921408 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 78411921408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125924198400).

78411921408 is an abundant number, since it is smaller than the sum of its proper divisors (173436475392).

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

78411921408 is a wasteful number, since it uses less digits than its factorization.

78411921408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The spelling of 78411921408 in words is "seventy-eight billion, four hundred eleven million, nine hundred twenty-one thousand, four hundred eight".