6640156 has 6 divisors (see below), whose sum is σ = 11620280. Its totient is φ = 3320076.

The previous prime is 6640129. The next prime is 6640157. The reversal of 6640156 is 6510466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830016 + ... + 830023.

Almost surely, 2^6640156 is an apocalyptic number.

It is an amenable number.

6640156 is a deficient number, since it is larger than the sum of its proper divisors (4980124).

6640156 is a wasteful number, since it uses less digits than its factorization.

6640156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660043 (or 1660041 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 6640156 is about 2576.8500150377. The cubic root of 6640156 is about 187.9573994315.

The spelling of 6640156 in words is "six million, six hundred forty thousand, one hundred fifty-six".