15642484857 has 20 divisors (see below), whose sum is σ = 23998718436. Its totient is φ = 10146474720.

The previous prime is 15642484849. The next prime is 15642484867. The reversal of 15642484857 is 75848424651.

15642484857 is a `hidden beast` number, since 1 + 564 + 24 + 8 + 4 + 8 + 57 = 666.

15642484857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 5798670201 + 9843814656 = 76149^2 + 99216^2 .

It is not a de Polignac number, because 15642484857 - 2³ = 15642484849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (15642484807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2606694 + ... + 2612687.

Almost surely, 2^15642484857 is an apocalyptic number.

It is an amenable number.

15642484857 is a deficient number, since it is larger than the sum of its proper divisors (8356233579).

15642484857 is an equidigital number, since it uses as much as digits as its factorization.

15642484857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5219430 (or 5219421 counting only the distinct ones).

The product of its digits is 8601600, while the sum is 54.

The spelling of 15642484857 in words is "fifteen billion, six hundred forty-two million, four hundred eighty-four thousand, eight hundred fifty-seven".