78394921750 has 16 divisors (see below), whose sum is σ = 146755293984. Its totient is φ = 31357968600.

The previous prime is 78394921729. The next prime is 78394921763. The reversal of 78394921750 is 5712949387.

It is a happy number.

It is a super-2 number, since 2×78394921750² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78394921691 and 78394921700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156789594 + ... + 156790093.

It is an arithmetic number, because the mean of its divisors is an integer number (9172205874).

Almost surely, 2^78394921750 is an apocalyptic number.

78394921750 is a deficient number, since it is larger than the sum of its proper divisors (68360372234).

78394921750 is a wasteful number, since it uses less digits than its factorization.

78394921750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313579704 (or 313579694 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 55.

The spelling of 78394921750 in words is "seventy-eight billion, three hundred ninety-four million, nine hundred twenty-one thousand, seven hundred fifty".