78934499721 has 24 divisors (see below), whose sum is σ = 142150442304. Its totient is φ = 41004934560.

The previous prime is 78934499717. The next prime is 78934499753. The reversal of 78934499721 is 12799443987.

78934499721 is a `hidden beast` number, since 7 + 89 + 3 + 449 + 97 + 21 = 666.

It is not a de Polignac number, because 78934499721 - 2² = 78934499717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (78934499701) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56950606 + ... + 56951991.

It is an arithmetic number, because the mean of its divisors is an integer number (5922935096).

Almost surely, 2^78934499721 is an apocalyptic number.

It is an amenable number.

78934499721 is a deficient number, since it is larger than the sum of its proper divisors (63215942583).

78934499721 is a wasteful number, since it uses less digits than its factorization.

78934499721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113902621 (or 113902618 counting only the distinct ones).

The product of its digits is 27433728, while the sum is 63.

The spelling of 78934499721 in words is "seventy-eight billion, nine hundred thirty-four million, four hundred ninety-nine thousand, seven hundred twenty-one".