78472256641 has 3 divisors (see below), whose sum is σ = 78472536771. Its totient is φ = 78471976512.

The previous prime is 78472256617. The next prime is 78472256647. The reversal of 78472256641 is 14665227487.

The square root of 78472256641 is 280129.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 14665227487 = 613 ⋅23923699.

It can be written as a sum of positive squares in only one way, i.e., 32642010241 + 45830246400 = 180671^2 + 214080^2 .

It is not a de Polignac number, because 78472256641 - 2²⁹ = 77935385729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78472256647) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 140065 + ... + 420193.

It is an arithmetic number, because the mean of its divisors is an integer number (26157512257).

Almost surely, 2^78472256641 is an apocalyptic number.

78472256641 is the 280129-th square number.

78472256641 is the 140065-th centered octagonal number.

It is an amenable number.

78472256641 is a deficient number, since it is larger than the sum of its proper divisors (280130).

78472256641 is an frugal number, since it uses more digits than its factorization.

78472256641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560258 (or 280129 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 52.

The spelling of 78472256641 in words is "seventy-eight billion, four hundred seventy-two million, two hundred fifty-six thousand, six hundred forty-one".