66905472 has 128 divisors (see below), whose sum is σ = 193955040. Its totient is φ = 20348928.

The previous prime is 66905467. The next prime is 66905473. The reversal of 66905472 is 27450966.

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

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 a self number, because there is not a number n which added to its sum of digits gives 66905472.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66905473) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241398 + ... + 241674.

Almost surely, 2^66905472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66905472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96977520).

66905472 is an abundant number, since it is smaller than the sum of its proper divisors (127049568).

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

66905472 is a wasteful number, since it uses less digits than its factorization.

66905472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 66905472 is about 8179.5765171554. The cubic root of 66905472 is about 405.9637101847.

The spelling of 66905472 in words is "sixty-six million, nine hundred five thousand, four hundred seventy-two".