66813528 has 32 divisors (see below), whose sum is σ = 174297600. Its totient is φ = 21302688.

The previous prime is 66813521. The next prime is 66813533. The reversal of 66813528 is 82531866.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66813521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59968 + ... + 61071.

It is an arithmetic number, because the mean of its divisors is an integer number (5446800).

Almost surely, 2^66813528 is an apocalyptic number.

It is an amenable number.

66813528 is an abundant number, since it is smaller than the sum of its proper divisors (107484072).

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

66813528 is a wasteful number, since it uses less digits than its factorization.

66813528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121071 (or 121067 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 66813528 is about 8173.9542450395. The cubic root of 66813528 is about 405.7776614329. Note that the first 3 decimals are identical.

It can be divided in two parts, 668 and 13528, that added together give a triangular number (14196 = T₁₆₈).

The spelling of 66813528 in words is "sixty-six million, eight hundred thirteen thousand, five hundred twenty-eight".