66662139 has 4 divisors (see below), whose sum is σ = 88882856. Its totient is φ = 44441424.

The previous prime is 66662137. The next prime is 66662143. The reversal of 66662139 is 93126666.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66662139 - 2¹ = 66662137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66662097 and 66662106.

It is not an unprimeable number, because it can be changed into a prime (66662137) 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, 11110354 + ... + 11110359.

It is an arithmetic number, because the mean of its divisors is an integer number (22220714).

Almost surely, 2^66662139 is an apocalyptic number.

66662139 is a deficient number, since it is larger than the sum of its proper divisors (22220717).

66662139 is a wasteful number, since it uses less digits than its factorization.

66662139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22220716.

The product of its digits is 69984, while the sum is 39.

The square root of 66662139 is about 8164.6885427431. The cubic root of 66662139 is about 405.4709534360.

The spelling of 66662139 in words is "sixty-six million, six hundred sixty-two thousand, one hundred thirty-nine".