665406156 has 24 divisors (see below), whose sum is σ = 1561916160. Its totient is φ = 220473232.

The previous prime is 665406121. The next prime is 665406173. The reversal of 665406156 is 651604566.

665406156 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164016 + ... + 168023.

It is an arithmetic number, because the mean of its divisors is an integer number (65079840).

Almost surely, 2^665406156 is an apocalyptic number.

It is an amenable number.

665406156 is an abundant number, since it is smaller than the sum of its proper divisors (896510004).

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

665406156 is a wasteful number, since it uses less digits than its factorization.

665406156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332213 (or 332211 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 39.

The square root of 665406156 is about 25795.4677414464. The cubic root of 665406156 is about 873.0295386191.

The spelling of 665406156 in words is "six hundred sixty-five million, four hundred six thousand, one hundred fifty-six".