66621633 has 8 divisors (see below), whose sum is σ = 95661888. Its totient is φ = 40997904.

The previous prime is 66621617. The next prime is 66621641. The reversal of 66621633 is 33612666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66621633 - 2⁴ = 66621617 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66621594 and 66621603.

It is not an unprimeable number, because it can be changed into a prime (66620633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 854085 + ... + 854162.

It is an arithmetic number, because the mean of its divisors is an integer number (11957736).

Almost surely, 2^66621633 is an apocalyptic number.

It is an amenable number.

66621633 is a deficient number, since it is larger than the sum of its proper divisors (29040255).

66621633 is a wasteful number, since it uses less digits than its factorization.

66621633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1708263.

The product of its digits is 23328, while the sum is 33.

The square root of 66621633 is about 8162.2076057890. The cubic root of 66621633 is about 405.3888111866.

The spelling of 66621633 in words is "sixty-six million, six hundred twenty-one thousand, six hundred thirty-three".