478731993 has 4 divisors (see below), whose sum is σ = 638309328. Its totient is φ = 319154660.

The previous prime is 478731991. The next prime is 478731997. The reversal of 478731993 is 399137874.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 478731993 - 2¹ = 478731991 is a prime.

It is a super-2 number, since 2×478731993² = 458368642243504098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (478731991) 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, 79788663 + ... + 79788668.

It is an arithmetic number, because the mean of its divisors is an integer number (159577332).

Almost surely, 2^478731993 is an apocalyptic number.

It is an amenable number.

478731993 is a deficient number, since it is larger than the sum of its proper divisors (159577335).

478731993 is a wasteful number, since it uses less digits than its factorization.

478731993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159577334.

The product of its digits is 1143072, while the sum is 51.

The square root of 478731993 is about 21879.9449953605. The cubic root of 478731993 is about 782.2834647377.

The spelling of 478731993 in words is "four hundred seventy-eight million, seven hundred thirty-one thousand, nine hundred ninety-three".