66604451 has 4 divisors (see below), whose sum is σ = 67733400. Its totient is φ = 65475504.

The previous prime is 66604427. The next prime is 66604501. The reversal of 66604451 is 15440666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66604451 - 2²² = 62410147 is a prime.

It is a super-2 number, since 2×66604451² = 8872305786022802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66604051) 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, 564386 + ... + 564503.

It is an arithmetic number, because the mean of its divisors is an integer number (16933350).

Almost surely, 2^66604451 is an apocalyptic number.

66604451 is a deficient number, since it is larger than the sum of its proper divisors (1128949).

66604451 is a wasteful number, since it uses less digits than its factorization.

66604451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128948.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 66604451 is about 8161.1550040420. The cubic root of 66604451 is about 405.3539576957.

It can be divided in two parts, 6660 and 4451, that added together give a palindrome (11111).

The spelling of 66604451 in words is "sixty-six million, six hundred four thousand, four hundred fifty-one".