78218582510721 has 16 divisors (see below), whose sum is σ = 110565296526848. Its totient is φ = 49099720492800.

The previous prime is 78218582510711. The next prime is 78218582510723. The reversal of 78218582510721 is 12701528581287.

It is not a de Polignac number, because 78218582510721 - 2²⁶ = 78218515401857 is a prime.

It is a super-2 number, since 2×78218582510721² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78218582510723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11365672600 + ... + 11365679481.

It is an arithmetic number, because the mean of its divisors is an integer number (6910331032928).

Almost surely, 2^{78218582510721} is an apocalyptic number.

It is an amenable number.

78218582510721 is a deficient number, since it is larger than the sum of its proper divisors (32346714016127).

78218582510721 is a wasteful number, since it uses less digits than its factorization.

78218582510721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22731352152.

The product of its (nonzero) digits is 5017600, while the sum is 57.

The spelling of 78218582510721 in words is "seventy-eight trillion, two hundred eighteen billion, five hundred eighty-two million, five hundred ten thousand, seven hundred twenty-one".