66257988 has 12 divisors (see below), whose sum is σ = 154602000. Its totient is φ = 22085992.

The previous prime is 66257929. The next prime is 66258029. The reversal of 66257988 is 88975266.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 66257988.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2760738 + ... + 2760761.

It is an arithmetic number, because the mean of its divisors is an integer number (12883500).

Almost surely, 2^66257988 is an apocalyptic number.

It is an amenable number.

66257988 is an abundant number, since it is smaller than the sum of its proper divisors (88344012).

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

66257988 is a wasteful number, since it uses less digits than its factorization.

66257988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5521506 (or 5521504 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 51.

The square root of 66257988 is about 8139.9009821987. The cubic root of 66257988 is about 404.6498787833.

The spelling of 66257988 in words is "sixty-six million, two hundred fifty-seven thousand, nine hundred eighty-eight".