78105251647 has 4 divisors (see below), whose sum is σ = 78105997480. Its totient is φ = 78104505816.

The previous prime is 78105251641. The next prime is 78105251659. The reversal of 78105251647 is 74615250187.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78105251647 - 2¹⁵ = 78105218879 is a prime.

It is a super-2 number, since 2×78105251647² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78105251597 and 78105251606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78105251641) 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, 183897 + ... + 435922.

It is an arithmetic number, because the mean of its divisors is an integer number (19526499370).

Almost surely, 2^78105251647 is an apocalyptic number.

78105251647 is a deficient number, since it is larger than the sum of its proper divisors (745833).

78105251647 is a wasteful number, since it uses less digits than its factorization.

78105251647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745832.

The product of its (nonzero) digits is 470400, while the sum is 46.

The spelling of 78105251647 in words is "seventy-eight billion, one hundred five million, two hundred fifty-one thousand, six hundred forty-seven".