668608240 has 20 divisors (see below), whose sum is σ = 1554514344. Its totient is φ = 267443264.

The previous prime is 668608201. The next prime is 668608273. The reversal of 668608240 is 42806866.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 668608193 and 668608202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4178722 + ... + 4178881.

Almost surely, 2^668608240 is an apocalyptic number.

It is an amenable number.

668608240 is an abundant number, since it is smaller than the sum of its proper divisors (885906104).

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

668608240 is a wasteful number, since it uses less digits than its factorization.

668608240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8357616 (or 8357610 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 668608240 is about 25857.4600454105. The cubic root of 668608240 is about 874.4277030476.

The spelling of 668608240 in words is "six hundred sixty-eight million, six hundred eight thousand, two hundred forty".