78379852721 has 8 divisors (see below), whose sum is σ = 78565173960. Its totient is φ = 78194737152.

The previous prime is 78379852697. The next prime is 78379852723. The reversal of 78379852721 is 12725897387.

It can be written as a sum of positive squares in 4 ways, for example, as 2281113121 + 76098739600 = 47761^2 + 275860^2 .

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-78379852721 is a prime.

It is a super-2 number, since 2×78379852721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78379852723) 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, 725465 + ... + 826473.

It is an arithmetic number, because the mean of its divisors is an integer number (9820646745).

Almost surely, 2^78379852721 is an apocalyptic number.

It is an amenable number.

78379852721 is a deficient number, since it is larger than the sum of its proper divisors (185321239).

78379852721 is a wasteful number, since it uses less digits than its factorization.

78379852721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102835.

The product of its digits is 11854080, while the sum is 59.

The spelling of 78379852721 in words is "seventy-eight billion, three hundred seventy-nine million, eight hundred fifty-two thousand, seven hundred twenty-one".