66658944 has 128 divisors (see below), whose sum is σ = 198190080. Its totient is φ = 19676160.

The previous prime is 66658939. The next prime is 66658951. The reversal of 66658944 is 44985666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 66658893 and 66658902.

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 15 ways as a sum of consecutive naturals, for example, 181449 + ... + 181815.

It is an arithmetic number, because the mean of its divisors is an integer number (1548360).

Almost surely, 2^66658944 is an apocalyptic number.

66658944 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66658944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99095040).

66658944 is an abundant number, since it is smaller than the sum of its proper divisors (131531136).

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

66658944 is a wasteful number, since it uses less digits than its factorization.

66658944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438 (or 426 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 48.

The square root of 66658944 is about 8164.4928807612. The cubic root of 66658944 is about 405.4644754941.

The spelling of 66658944 in words is "sixty-six million, six hundred fifty-eight thousand, nine hundred forty-four".