478131921 has 24 divisors (see below), whose sum is σ = 720061056. Its totient is φ = 305454240.

The previous prime is 478131917. The next prime is 478131947. The reversal of 478131921 is 129131874.

It is a happy number.

It is not a de Polignac number, because 478131921 - 2² = 478131917 is a prime.

It is a super-2 number, since 2×478131921² = 457220267758300482, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (478131991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8856 + ... + 32166.

It is an arithmetic number, because the mean of its divisors is an integer number (30002544).

Almost surely, 2^478131921 is an apocalyptic number.

It is an amenable number.

478131921 is a deficient number, since it is larger than the sum of its proper divisors (241929135).

478131921 is a wasteful number, since it uses less digits than its factorization.

478131921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23413 (or 23410 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 478131921 is about 21866.2278639915. The cubic root of 478131921 is about 781.9564740744.

The spelling of 478131921 in words is "four hundred seventy-eight million, one hundred thirty-one thousand, nine hundred twenty-one".