478621793581 has 2 divisors, whose sum is σ = 478621793582. Its totient is φ = 478621793580.

The previous prime is 478621793579. The next prime is 478621793597. The reversal of 478621793581 is 185397126874.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 439668455625 + 38953337956 = 663075^2 + 197366^2 .

It is a cyclic number.

It is not a de Polignac number, because 478621793581 - 2¹ = 478621793579 is a prime.

It is a super-2 number, since 2×478621793581² (a number of 24 digits) contains 22 as substring.

Together with 478621793579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (478621793081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 239310896790 + 239310896791.

It is an arithmetic number, because the mean of its divisors is an integer number (239310896791).

Almost surely, 2^478621793581 is an apocalyptic number.

It is an amenable number.

478621793581 is a deficient number, since it is larger than the sum of its proper divisors (1).

478621793581 is an equidigital number, since it uses as much as digits as its factorization.

478621793581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20321280, while the sum is 61.

The spelling of 478621793581 in words is "four hundred seventy-eight billion, six hundred twenty-one million, seven hundred ninety-three thousand, five hundred eighty-one".