66838355 has 4 divisors (see below), whose sum is σ = 80206032. Its totient is φ = 53470680.

The previous prime is 66838319. The next prime is 66838361. The reversal of 66838355 is 55383866.

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

It is a de Polignac number, because none of the positive numbers 2^k-66838355 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6683831 + ... + 6683840.

It is an arithmetic number, because the mean of its divisors is an integer number (20051508).

Almost surely, 2^66838355 is an apocalyptic number.

66838355 is a deficient number, since it is larger than the sum of its proper divisors (13367677).

66838355 is a wasteful number, since it uses less digits than its factorization.

66838355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13367676.

The product of its digits is 518400, while the sum is 44.

The square root of 66838355 is about 8175.4727692042. The cubic root of 66838355 is about 405.8279156989.

Adding to 66838355 its reverse (55383866), we get a palindrome (122222221).

The spelling of 66838355 in words is "sixty-six million, eight hundred thirty-eight thousand, three hundred fifty-five".