78645471844 has 27 divisors (see below), whose sum is σ = 138398454201. Its totient is φ = 39104274720.

The previous prime is 78645471829. The next prime is 78645471847. The reversal of 78645471844 is 44817454687.

The square root of 78645471844 is 280438.

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., 53147769444 + 25497702400 = 230538^2 + 159680^2 .

It is a super-2 number, since 2×78645471844² (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 (78645471847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 157605907 + ... + 157606405.

Almost surely, 2^78645471844 is an apocalyptic number.

78645471844 is the 280438-th square number.

It is an amenable number.

78645471844 is a deficient number, since it is larger than the sum of its proper divisors (59752982357).

78645471844 is an frugal number, since it uses more digits than its factorization.

78645471844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1564 (or 782 counting only the distinct ones).

The product of its digits is 24084480, while the sum is 58.

The spelling of 78645471844 in words is "seventy-eight billion, six hundred forty-five million, four hundred seventy-one thousand, eight hundred forty-four".