66820808 has 8 divisors (see below), whose sum is σ = 125289030. Its totient is φ = 33410400.

The previous prime is 66820763. The next prime is 66820811. The reversal of 66820808 is 80802866.

It can be written as a sum of positive squares in only one way, i.e., 39967684 + 26853124 = 6322^2 + 5182^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4176293 + ... + 4176308.

Almost surely, 2^66820808 is an apocalyptic number.

It is an amenable number.

66820808 is a deficient number, since it is larger than the sum of its proper divisors (58468222).

66820808 is a wasteful number, since it uses less digits than its factorization.

66820808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8352607 (or 8352603 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 66820808 is about 8174.3995498140. The cubic root of 66820808 is about 405.7923987382.

The spelling of 66820808 in words is "sixty-six million, eight hundred twenty thousand, eight hundred eight".