66685453 has 4 divisors (see below), whose sum is σ = 66739680. Its totient is φ = 66631228.

The previous prime is 66685447. The next prime is 66685457. The reversal of 66685453 is 35458666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35458666 = 2 ⋅17729333.

It is a cyclic number.

It is not a de Polignac number, because 66685453 - 2¹⁷ = 66554381 is a prime.

It is a super-4 number, since 4×66685453⁴ (a number of 32 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66685457) 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, 25225 + ... + 27742.

It is an arithmetic number, because the mean of its divisors is an integer number (16684920).

Almost surely, 2^66685453 is an apocalyptic number.

It is an amenable number.

66685453 is a deficient number, since it is larger than the sum of its proper divisors (54227).

66685453 is a wasteful number, since it uses less digits than its factorization.

66685453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54226.

The product of its digits is 518400, while the sum is 43.

The square root of 66685453 is about 8166.1161515129. The cubic root of 66685453 is about 405.5182168859.

It can be divided in two parts, 6668 and 5453, that added together give a palindrome (12121).

The spelling of 66685453 in words is "sixty-six million, six hundred eighty-five thousand, four hundred fifty-three".