78221875711066 has 4 divisors (see below), whose sum is σ = 117332813566602. Its totient is φ = 39110937855532.

The previous prime is 78221875710991. The next prime is 78221875711093. The reversal of 78221875711066 is 66011757812287.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 77951505870225 + 270369840841 = 8829015^2 + 519971^2 .

It is a super-2 number, since 2×78221875711066² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78221875710995 and 78221875711013.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19555468927765 + ... + 19555468927768.

Almost surely, 2^{78221875711066} is an apocalyptic number.

78221875711066 is a deficient number, since it is larger than the sum of its proper divisors (39110937855536).

78221875711066 is a wasteful number, since it uses less digits than its factorization.

78221875711066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39110937855535.

The product of its (nonzero) digits is 15805440, while the sum is 61.

The spelling of 78221875711066 in words is "seventy-eight trillion, two hundred twenty-one billion, eight hundred seventy-five million, seven hundred eleven thousand, sixty-six".