78320971 has 4 divisors (see below), whose sum is σ = 80437792. Its totient is φ = 76204152.

The previous prime is 78320959. The next prime is 78320981. The reversal of 78320971 is 17902387.

78320971 = 480² + 481² + ... + 701².

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

It is a cyclic number.

It is not a de Polignac number, because 78320971 - 2⁵ = 78320939 is a prime.

It is a super-2 number, since 2×78320971² = 12268348996765682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 2116783 = 78320971 / (7 + 8 + 3 + 2 + 0 + 9 + 7 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78320971.

It is not an unprimeable number, because it can be changed into a prime (78320981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1058355 + ... + 1058428.

It is an arithmetic number, because the mean of its divisors is an integer number (20109448).

Almost surely, 2^78320971 is an apocalyptic number.

78320971 is the 5110-th hex number.

78320971 is a deficient number, since it is larger than the sum of its proper divisors (2116821).

78320971 is a wasteful number, since it uses less digits than its factorization.

78320971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116820.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 78320971 is about 8849.9136153976. The cubic root of 78320971 is about 427.8511342850.

The spelling of 78320971 in words is "seventy-eight million, three hundred twenty thousand, nine hundred seventy-one".