66625455 has 32 divisors (see below), whose sum is σ = 116766720. Its totient is φ = 32238720.

The previous prime is 66625453. The next prime is 66625459. The reversal of 66625455 is 55452666.

It is a happy number.

It is not a de Polignac number, because 66625455 - 2¹ = 66625453 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66625453) 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 31 ways as a sum of consecutive naturals, for example, 8610 + ... + 14400.

It is an arithmetic number, because the mean of its divisors is an integer number (3648960).

Almost surely, 2^66625455 is an apocalyptic number.

66625455 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66625455 is a deficient number, since it is larger than the sum of its proper divisors (50141265).

66625455 is a wasteful number, since it uses less digits than its factorization.

66625455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5871.

The product of its digits is 216000, while the sum is 39.

The square root of 66625455 is about 8162.4417302667. The cubic root of 66625455 is about 405.3965632552.

It can be divided in two parts, 66 and 625455, that added together give a triangular number (625521 = T₁₁₁₈).

The spelling of 66625455 in words is "sixty-six million, six hundred twenty-five thousand, four hundred fifty-five".