66439661225 has 48 divisors (see below), whose sum is σ = 99543926400. Its totient is φ = 42971834880.

The previous prime is 66439661219. The next prime is 66439661231. The reversal of 66439661225 is 52216693466.

It is an interprime number because it is at equal distance from previous prime (66439661219) and next prime (66439661231).

It is not a de Polignac number, because 66439661225 - 2¹⁰ = 66439660201 is a prime.

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 47 ways as a sum of consecutive naturals, for example, 717797 + ... + 805053.

It is an arithmetic number, because the mean of its divisors is an integer number (2073831800).

Almost surely, 2^66439661225 is an apocalyptic number.

It is an amenable number.

66439661225 is a deficient number, since it is larger than the sum of its proper divisors (33104265175).

66439661225 is a wasteful number, since it uses less digits than its factorization.

66439661225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87522 (or 87517 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 50.

The spelling of 66439661225 in words is "sixty-six billion, four hundred thirty-nine million, six hundred sixty-one thousand, two hundred twenty-five".