478839661 has 4 divisors (see below), whose sum is σ = 482053500. Its totient is φ = 475625824.

The previous prime is 478839643. The next prime is 478839703. The reversal of 478839661 is 166938874.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166938874 = 2 ⋅83469437.

It can be written as a sum of positive squares in 2 ways, for example, as 86601636 + 392238025 = 9306^2 + 19805^2 .

It is a cyclic number.

It is not a de Polignac number, because 478839661 - 2²⁵ = 445285229 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 478839599 and 478839608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (478839611) 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, 1606696 + ... + 1606993.

It is an arithmetic number, because the mean of its divisors is an integer number (120513375).

Almost surely, 2^478839661 is an apocalyptic number.

It is an amenable number.

478839661 is a deficient number, since it is larger than the sum of its proper divisors (3213839).

478839661 is a wasteful number, since it uses less digits than its factorization.

478839661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3213838.

The product of its digits is 1741824, while the sum is 52.

The square root of 478839661 is about 21882.4052836977. The cubic root of 478839661 is about 782.3421061654.

The spelling of 478839661 in words is "four hundred seventy-eight million, eight hundred thirty-nine thousand, six hundred sixty-one".