66551625 has 96 divisors (see below), whose sum is σ = 142641408. Its totient is φ = 30326400.

The previous prime is 66551593. The next prime is 66551647. The reversal of 66551625 is 52615566.

It is a happy number.

It is not a de Polignac number, because 66551625 - 2⁵ = 66551593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66551625.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 212469 + ... + 212781.

It is an arithmetic number, because the mean of its divisors is an integer number (1485848).

Almost surely, 2^66551625 is an apocalyptic number.

It is an amenable number.

66551625 is an abundant number, since it is smaller than the sum of its proper divisors (76089783).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66551625 is an equidigital number, since it uses as much as digits as its factorization.

66551625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350 (or 328 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 66551625 is about 8157.9179329042. The cubic root of 66551625 is about 405.2467631989.

It can be divided in two parts, 66551 and 625, that added together give a palindrome (67176).

The spelling of 66551625 in words is "sixty-six million, five hundred fifty-one thousand, six hundred twenty-five".