1641665633 has 4 divisors (see below), whose sum is σ = 1652122260. Its totient is φ = 1631209008.

The previous prime is 1641665629. The next prime is 1641665647. The reversal of 1641665633 is 3365661461.

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

It can be written as a sum of positive squares in 2 ways, for example, as 214563904 + 1427101729 = 14648^2 + 37777^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641665633 - 2² = 1641665629 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1641665693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5228078 + ... + 5228391.

It is an arithmetic number, because the mean of its divisors is an integer number (413030565).

Almost surely, 2^1641665633 is an apocalyptic number.

It is an amenable number.

1641665633 is a deficient number, since it is larger than the sum of its proper divisors (10456627).

1641665633 is a wasteful number, since it uses less digits than its factorization.

1641665633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10456626.

The product of its digits is 233280, while the sum is 41.

The square root of 1641665633 is about 40517.4731813325. The cubic root of 1641665633 is about 1179.6728081160.

The spelling of 1641665633 in words is "one billion, six hundred forty-one million, six hundred sixty-five thousand, six hundred thirty-three".