66754521 has 6 divisors (see below), whose sum is σ = 96423210. Its totient is φ = 44503008.

The previous prime is 66754517. The next prime is 66754537. The reversal of 66754521 is 12545766.

It is a happy number.

66754521 is a `hidden beast` number, since 66 + 75 + 4 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 66585600 + 168921 = 8160^2 + 411^2 .

It is not a de Polignac number, because 66754521 - 2² = 66754517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66754561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3708576 + ... + 3708593.

It is an arithmetic number, because the mean of its divisors is an integer number (16070535).

Almost surely, 2^66754521 is an apocalyptic number.

It is an amenable number.

66754521 is a deficient number, since it is larger than the sum of its proper divisors (29668689).

66754521 is a wasteful number, since it uses less digits than its factorization.

66754521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7417175 (or 7417172 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 66754521 is about 8170.3439952061. The cubic root of 66754521 is about 405.6581707880.

The spelling of 66754521 in words is "sixty-six million, seven hundred fifty-four thousand, five hundred twenty-one".