78216323511538 has 32 divisors (see below), whose sum is σ = 118394891334720. Its totient is φ = 38753001154560.

The previous prime is 78216323511533. The next prime is 78216323511553. The reversal of 78216323511538 is 83511532361287.

It is a happy number.

It is a super-2 number, since 2×78216323511538² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78216323511533) 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, 2498349681 + ... + 2498380987.

It is an arithmetic number, because the mean of its divisors is an integer number (3699840354210).

Almost surely, 2^{78216323511538} is an apocalyptic number.

78216323511538 is a deficient number, since it is larger than the sum of its proper divisors (40178567823182).

78216323511538 is a wasteful number, since it uses less digits than its factorization.

78216323511538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57162.

The product of its digits is 7257600, while the sum is 55.

The spelling of 78216323511538 in words is "seventy-eight trillion, two hundred sixteen billion, three hundred twenty-three million, five hundred eleven thousand, five hundred thirty-eight".