666414388 has 6 divisors (see below), whose sum is σ = 1166225186. Its totient is φ = 333207192.

The previous prime is 666414373. The next prime is 666414389. The reversal of 666414388 is 883414666.

It can be written as a sum of positive squares in only one way, i.e., 629106724 + 37307664 = 25082^2 + 6108^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666414389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83301795 + ... + 83301802.

Almost surely, 2^666414388 is an apocalyptic number.

It is an amenable number.

666414388 is a deficient number, since it is larger than the sum of its proper divisors (499810798).

666414388 is a wasteful number, since it uses less digits than its factorization.

666414388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166603601 (or 166603599 counting only the distinct ones).

The product of its digits is 663552, while the sum is 46.

The square root of 666414388 is about 25815.0031570790. The cubic root of 666414388 is about 873.4702579763.

The spelling of 666414388 in words is "six hundred sixty-six million, four hundred fourteen thousand, three hundred eighty-eight".