66170521 has 16 divisors (see below), whose sum is σ = 71280000. Its totient is φ = 61243776.

The previous prime is 66170519. The next prime is 66170539. The reversal of 66170521 is 12507166.

It is a cyclic number.

It is not a de Polignac number, because 66170521 - 2¹ = 66170519 is a prime.

It is a super-2 number, since 2×66170521² = 8757075698822882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66170521.

It is not an unprimeable number, because it can be changed into a prime (66170581) 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, 184140 + ... + 184498.

It is an arithmetic number, because the mean of its divisors is an integer number (4455000).

Almost surely, 2^66170521 is an apocalyptic number.

It is an amenable number.

66170521 is a deficient number, since it is larger than the sum of its proper divisors (5109479).

66170521 is a wasteful number, since it uses less digits than its factorization.

66170521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 66170521 is about 8134.5264766918. The cubic root of 66170521 is about 404.4717412850.

Adding to 66170521 its reverse (12507166), we get a palindrome (78677687).

The spelling of 66170521 in words is "sixty-six million, one hundred seventy thousand, five hundred twenty-one".