66031640 has 32 divisors (see below), whose sum is σ = 151379280. Its totient is φ = 25913472.

The previous prime is 66031627. The next prime is 66031687. The reversal of 66031640 is 4613066.

66031640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 13454 + ... + 17693.

Almost surely, 2^66031640 is an apocalyptic number.

It is an amenable number.

66031640 is an abundant number, since it is smaller than the sum of its proper divisors (85347640).

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

66031640 is a wasteful number, since it uses less digits than its factorization.

66031640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31211 (or 31207 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 66031640 is about 8125.9854786973. The cubic root of 66031640 is about 404.1885699446.

The spelling of 66031640 in words is "sixty-six million, thirty-one thousand, six hundred forty".