78499861645 has 16 divisors (see below), whose sum is σ = 96015553200. Its totient is φ = 61590357504.

The previous prime is 78499861619. The next prime is 78499861721. The reversal of 78499861645 is 54616899487.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2472277284 + 76027584361 = 49722^2 + 275731^2 .

It is a cyclic number.

It is not a de Polignac number, because 78499861645 - 2⁹ = 78499861133 is a prime.

It is a super-3 number, since 3×78499861645³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 619681 + ... + 735529.

It is an arithmetic number, because the mean of its divisors is an integer number (6000972075).

Almost surely, 2^78499861645 is an apocalyptic number.

It is an amenable number.

78499861645 is a deficient number, since it is larger than the sum of its proper divisors (17515691555).

78499861645 is a wasteful number, since it uses less digits than its factorization.

78499861645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118464.

The product of its digits is 104509440, while the sum is 67.

The spelling of 78499861645 in words is "seventy-eight billion, four hundred ninety-nine million, eight hundred sixty-one thousand, six hundred forty-five".