478320781 has 4 divisors (see below), whose sum is σ = 478572732. Its totient is φ = 478068832.

The previous prime is 478320779. The next prime is 478320803. The reversal of 478320781 is 187023874.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187023874 = 2 ⋅93511937.

It can be written as a sum of positive squares in 2 ways, for example, as 162690025 + 315630756 = 12755^2 + 17766^2 .

It is a cyclic number.

It is not a de Polignac number, because 478320781 - 2¹ = 478320779 is a prime.

It is a super-2 number, since 2×478320781² = 457581539072899922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (478320881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123106 + ... + 126931.

It is an arithmetic number, because the mean of its divisors is an integer number (119643183).

Almost surely, 2^478320781 is an apocalyptic number.

It is an amenable number.

478320781 is a deficient number, since it is larger than the sum of its proper divisors (251951).

478320781 is a wasteful number, since it uses less digits than its factorization.

478320781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251950.

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 478320781 is about 21870.5459694083. The cubic root of 478320781 is about 782.0594169744.

The spelling of 478320781 in words is "four hundred seventy-eight million, three hundred twenty thousand, seven hundred eighty-one".