66451605 has 32 divisors (see below), whose sum is σ = 117739008. Its totient is φ = 31732800.

The previous prime is 66451603. The next prime is 66451613. The reversal of 66451605 is 50615466.

It is not a de Polignac number, because 66451605 - 2¹ = 66451603 is a prime.

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 (66451603) 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 31 ways as a sum of consecutive naturals, for example, 8050 + ... + 14060.

It is an arithmetic number, because the mean of its divisors is an integer number (3679344).

Almost surely, 2^66451605 is an apocalyptic number.

It is an amenable number.

66451605 is a deficient number, since it is larger than the sum of its proper divisors (51287403).

66451605 is a wasteful number, since it uses less digits than its factorization.

66451605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6097.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 66451605 is about 8151.7853872633. The cubic root of 66451605 is about 405.0436471783.

The spelling of 66451605 in words is "sixty-six million, four hundred fifty-one thousand, six hundred five".