66564121 has 8 divisors (see below), whose sum is σ = 71845760. Its totient is φ = 61305552.

The previous prime is 66564103. The next prime is 66564143. The reversal of 66564121 is 12146566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66564121 - 2¹⁹ = 66039833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66564521) 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, 490 + ... + 11548.

It is an arithmetic number, because the mean of its divisors is an integer number (8980720).

Almost surely, 2^66564121 is an apocalyptic number.

It is an amenable number.

66564121 is a deficient number, since it is larger than the sum of its proper divisors (5281639).

66564121 is a wasteful number, since it uses less digits than its factorization.

66564121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11535.

The product of its digits is 8640, while the sum is 31.

The square root of 66564121 is about 8158.6837786496. The cubic root of 66564121 is about 405.2721251974.

It can be divided in two parts, 66564 and 121, that multiplied together give a square (8054244 = 2838²).

The spelling of 66564121 in words is "sixty-six million, five hundred sixty-four thousand, one hundred twenty-one".