78615724509 has 240 divisors, whose sum is σ = 147015302720. Its totient is φ = 40327580160.

The previous prime is 78615724493. The next prime is 78615724553. The reversal of 78615724509 is 90542751687.

78615724509 is a `hidden beast` number, since 7 + 8 + 61 + 5 + 72 + 4 + 509 = 666.

It is not a de Polignac number, because 78615724509 - 2⁴ = 78615724493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78615744509) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 1076927697 + ... + 1076927769.

Almost surely, 2^78615724509 is an apocalyptic number.

It is an amenable number.

78615724509 is a deficient number, since it is larger than the sum of its proper divisors (68399578211).

78615724509 is a wasteful number, since it uses less digits than its factorization.

78615724509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 54.

The spelling of 78615724509 in words is "seventy-eight billion, six hundred fifteen million, seven hundred twenty-four thousand, five hundred nine".