78251778707538 has 8 divisors (see below), whose sum is σ = 156503557415088. Its totient is φ = 26083926235844.

The previous prime is 78251778707533. The next prime is 78251778707539. The reversal of 78251778707538 is 83570787715287.

It is a sphenic number, since it is the product of 3 distinct primes.

78251778707538 is an admirable number.

It is a super-2 number, since 2×78251778707538² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78251778707538.

It is not an unprimeable number, because it can be changed into a prime (78251778707533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6520981558956 + ... + 6520981558967.

It is an arithmetic number, because the mean of its divisors is an integer number (19562944676886).

Almost surely, 2^{78251778707538} is an apocalyptic number.

78251778707538 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

78251778707538 is a wasteful number, since it uses less digits than its factorization.

78251778707538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13041963117928.

The product of its (nonzero) digits is 1290777600, while the sum is 75.

The spelling of 78251778707538 in words is "seventy-eight trillion, two hundred fifty-one billion, seven hundred seventy-eight million, seven hundred seven thousand, five hundred thirty-eight".