78017399424 has 128 divisors (see below), whose sum is σ = 237687744000. Its totient is φ = 25166868480.

The previous prime is 78017399417. The next prime is 78017399429. The reversal of 78017399424 is 42499371087.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×78017399424² (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 not an unprimeable number, because it can be changed into a prime (78017399429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256969 + ... + 471240.

It is an arithmetic number, because the mean of its divisors is an integer number (1856935500).

Almost surely, 2^78017399424 is an apocalyptic number.

It is an amenable number.

78017399424 is an abundant number, since it is smaller than the sum of its proper divisors (159670344576).

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

78017399424 is a wasteful number, since it uses less digits than its factorization.

78017399424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728263 (or 728245 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The spelling of 78017399424 in words is "seventy-eight billion, seventeen million, three hundred ninety-nine thousand, four hundred twenty-four".