66655438 has 4 divisors (see below), whose sum is σ = 99983160. Its totient is φ = 33327718.

The previous prime is 66655429. The next prime is 66655441. The reversal of 66655438 is 83455666.

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

It is a junction number, because it is equal to n+sod(n) for n = 66655394 and 66655403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16663858 + ... + 16663861.

It is an arithmetic number, because the mean of its divisors is an integer number (24995790).

Almost surely, 2^66655438 is an apocalyptic number.

66655438 is a deficient number, since it is larger than the sum of its proper divisors (33327722).

66655438 is a wasteful number, since it uses less digits than its factorization.

66655438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33327721.

The product of its digits is 518400, while the sum is 43.

The square root of 66655438 is about 8164.2781677255. The cubic root of 66655438 is about 405.4573667537.

The spelling of 66655438 in words is "sixty-six million, six hundred fifty-five thousand, four hundred thirty-eight".