66400625 has 20 divisors (see below), whose sum is σ = 83710704. Its totient is φ = 52650000.

The previous prime is 66400601. The next prime is 66400627. The reversal of 66400625 is 52600466.

It is not a de Polignac number, because 66400625 - 2¹⁰ = 66399601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66400627) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 81470 + ... + 82280.

Almost surely, 2^66400625 is an apocalyptic number.

It is an amenable number.

66400625 is a deficient number, since it is larger than the sum of its proper divisors (17310079).

66400625 is an equidigital number, since it uses as much as digits as its factorization.

66400625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 962 (or 947 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 66400625 is about 8148.6578649493. The cubic root of 66400625 is about 404.9400409128.

The spelling of 66400625 in words is "sixty-six million, four hundred thousand, six hundred twenty-five".