66216604 has 6 divisors (see below), whose sum is σ = 115879064. Its totient is φ = 33108300.

The previous prime is 66216593. The next prime is 66216607. The reversal of 66216604 is 40661266.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66216607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8277072 + ... + 8277079.

Almost surely, 2^66216604 is an apocalyptic number.

It is an amenable number.

66216604 is a deficient number, since it is larger than the sum of its proper divisors (49662460).

66216604 is a wasteful number, since it uses less digits than its factorization.

66216604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16554155 (or 16554153 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 66216604 is about 8137.3585394770. The cubic root of 66216604 is about 404.5656146377.

It can be divided in two parts, 6621 and 6604, that added together give a square (13225 = 115²).

The spelling of 66216604 in words is "sixty-six million, two hundred sixteen thousand, six hundred four".