66445253 has 4 divisors (see below), whose sum is σ = 75937440. Its totient is φ = 56953068.

The previous prime is 66445237. The next prime is 66445259. The reversal of 66445253 is 35254466.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 66445253 - 2⁴ = 66445237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66445259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4746083 + ... + 4746096.

It is an arithmetic number, because the mean of its divisors is an integer number (18984360).

Almost surely, 2^66445253 is an apocalyptic number.

It is an amenable number.

66445253 is a deficient number, since it is larger than the sum of its proper divisors (9492187).

66445253 is an equidigital number, since it uses as much as digits as its factorization.

66445253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9492186.

The product of its digits is 86400, while the sum is 35.

The square root of 66445253 is about 8151.3957700507. The cubic root of 66445253 is about 405.0307409476.

The spelling of 66445253 in words is "sixty-six million, four hundred forty-five thousand, two hundred fifty-three".