66529221 has 16 divisors (see below), whose sum is σ = 97393728. Its totient is φ = 40060800.

The previous prime is 66529181. The next prime is 66529247. The reversal of 66529221 is 12292566.

It is not a de Polignac number, because 66529221 - 2⁷ = 66529093 is a prime.

It is a super-2 number, since 2×66529221² = 8852274493733682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66529291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1240 + ... + 11601.

It is an arithmetic number, because the mean of its divisors is an integer number (6087108).

Almost surely, 2^66529221 is an apocalyptic number.

It is an amenable number.

66529221 is a deficient number, since it is larger than the sum of its proper divisors (30864507).

66529221 is a wasteful number, since it uses less digits than its factorization.

66529221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13012.

The product of its digits is 12960, while the sum is 33.

The square root of 66529221 is about 8156.5446728379. The cubic root of 66529221 is about 405.2012838813.

The spelling of 66529221 in words is "sixty-six million, five hundred twenty-nine thousand, two hundred twenty-one".