78211706186 has 4 divisors (see below), whose sum is σ = 117317559282. Its totient is φ = 39105853092.

The previous prime is 78211706143. The next prime is 78211706197. The reversal of 78211706186 is 68160711287.

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., 58017875161 + 20193831025 = 240869^2 + 142105^2 .

It is a super-2 number, since 2×78211706186² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78211706186.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19552926545 + ... + 19552926548.

Almost surely, 2^78211706186 is an apocalyptic number.

78211706186 is a deficient number, since it is larger than the sum of its proper divisors (39105853096).

78211706186 is a wasteful number, since it uses less digits than its factorization.

78211706186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39105853095.

The product of its (nonzero) digits is 225792, while the sum is 47.

The spelling of 78211706186 in words is "seventy-eight billion, two hundred eleven million, seven hundred six thousand, one hundred eighty-six".