66752521 has 4 divisors (see below), whose sum is σ = 72820944. Its totient is φ = 60684100.

The previous prime is 66752503. The next prime is 66752527. The reversal of 66752521 is 12525766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66752521 - 2⁹ = 66752009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66752527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3034195 + ... + 3034216.

It is an arithmetic number, because the mean of its divisors is an integer number (18205236).

Almost surely, 2^66752521 is an apocalyptic number.

It is an amenable number.

66752521 is a deficient number, since it is larger than the sum of its proper divisors (6068423).

66752521 is a wasteful number, since it uses less digits than its factorization.

66752521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6068422.

The product of its digits is 25200, while the sum is 34.

The square root of 66752521 is about 8170.2216004219. The cubic root of 66752521 is about 405.6541195046.

The spelling of 66752521 in words is "sixty-six million, seven hundred fifty-two thousand, five hundred twenty-one".