66621608 has 32 divisors (see below), whose sum is σ = 129132360. Its totient is φ = 32198400.

The previous prime is 66621587. The next prime is 66621617. The reversal of 66621608 is 80612666.

It can be written as a sum of positive squares in 4 ways, for example, as 60871204 + 5750404 = 7802^2 + 2398^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50558 + ... + 51858.

Almost surely, 2^66621608 is an apocalyptic number.

It is an amenable number.

66621608 is a deficient number, since it is larger than the sum of its proper divisors (62510752).

66621608 is a wasteful number, since it uses less digits than its factorization.

66621608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1517 (or 1513 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 66621608 is about 8162.2060743404. The cubic root of 66621608 is about 405.3887604787.

The spelling of 66621608 in words is "sixty-six million, six hundred twenty-one thousand, six hundred eight".