78218664976 has 45 divisors (see below), whose sum is σ = 157019806333. Its totient is φ = 37745072960.

The previous prime is 78218664959. The next prime is 78218664977. The reversal of 78218664976 is 67946681287.

The square root of 78218664976 is 279676.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 41015970576 + 37202694400 = 202524^2 + 192880^2 .

It is a super-2 number, since 2×78218664976² (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 (78218664977) 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 8 ways as a sum of consecutive naturals, for example, 32441211 + ... + 32443621.

Almost surely, 2^78218664976 is an apocalyptic number.

78218664976 is the 279676-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78218664976

78218664976 is an abundant number, since it is smaller than the sum of its proper divisors (78801141357).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78218664976 is an frugal number, since it uses more digits than its factorization.

78218664976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4888 (or 2442 counting only the distinct ones).

The product of its digits is 48771072, while the sum is 64.

Multiplying 78218664976 by its sum of digits (64), we get a square (5005994558464 = 2237408²).

The spelling of 78218664976 in words is "seventy-eight billion, two hundred eighteen million, six hundred sixty-four thousand, nine hundred seventy-six".