668615240 has 16 divisors (see below), whose sum is σ = 1504384380. Its totient is φ = 267446080.

The previous prime is 668615203. The next prime is 668615243. The reversal of 668615240 is 42516866.

It can be written as a sum of positive squares in 2 ways, for example, as 651985156 + 16630084 = 25534^2 + 4078^2 .

It is a junction number, because it is equal to n+sod(n) for n = 668615194 and 668615203.

It is not an unprimeable number, because it can be changed into a prime (668615243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8357651 + ... + 8357730.

Almost surely, 2^668615240 is an apocalyptic number.

It is an amenable number.

668615240 is an abundant number, since it is smaller than the sum of its proper divisors (835769140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668615240 is a wasteful number, since it uses less digits than its factorization.

668615240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16715392 (or 16715388 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 668615240 is about 25857.5954025118. The cubic root of 668615240 is about 874.4307546465.

The spelling of 668615240 in words is "six hundred sixty-eight million, six hundred fifteen thousand, two hundred forty".