78711750221 has 8 divisors (see below), whose sum is σ = 86156115864. Its totient is φ = 71465901120.

The previous prime is 78711750181. The next prime is 78711750233. The reversal of 78711750221 is 12205711787.

It can be written as a sum of positive squares in 4 ways, for example, as 3045494596 + 75666255625 = 55186^2 + 275075^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78711750221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78716750221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49628306 + ... + 49629891.

It is an arithmetic number, because the mean of its divisors is an integer number (10769514483).

Almost surely, 2^78711750221 is an apocalyptic number.

It is an amenable number.

78711750221 is a deficient number, since it is larger than the sum of its proper divisors (7444365643).

78711750221 is a wasteful number, since it uses less digits than its factorization.

78711750221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99258271.

The product of its (nonzero) digits is 54880, while the sum is 41.

The spelling of 78711750221 in words is "seventy-eight billion, seven hundred eleven million, seven hundred fifty thousand, two hundred twenty-one".