78940628721 has 12 divisors (see below), whose sum is σ = 114662368080. Its totient is φ = 52333078680.

The previous prime is 78940628717. The next prime is 78940628777. The reversal of 78940628721 is 12782604987.

It is a happy number.

78940628721 is a `hidden beast` number, since 7 + 8 + 9 + 4 + 0 + 628 + 7 + 2 + 1 = 666.

It is not a de Polignac number, because 78940628721 - 2² = 78940628717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78940628791) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24498895 + ... + 24502116.

It is an arithmetic number, because the mean of its divisors is an integer number (9555197340).

Almost surely, 2^78940628721 is an apocalyptic number.

It is an amenable number.

78940628721 is a deficient number, since it is larger than the sum of its proper divisors (35721739359).

78940628721 is a wasteful number, since it uses less digits than its factorization.

78940628721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49001196 (or 49001193 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 78940628721 in words is "seventy-eight billion, nine hundred forty million, six hundred twenty-eight thousand, seven hundred twenty-one".