66616641 has 64 divisors (see below), whose sum is σ = 127948800. Its totient is φ = 33265728.

The previous prime is 66616631. The next prime is 66616651. The reversal of 66616641 is 14661666.

It is an interprime number because it is at equal distance from previous prime (66616631) and next prime (66616651).

It is not a de Polignac number, because 66616641 - 2⁵ = 66616609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66616596 and 66616605.

It is not an unprimeable number, because it can be changed into a prime (66616621) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 45970 + ... + 47396.

It is an arithmetic number, because the mean of its divisors is an integer number (1999200).

Almost surely, 2^66616641 is an apocalyptic number.

It is an amenable number.

66616641 is a deficient number, since it is larger than the sum of its proper divisors (61332159).

66616641 is a wasteful number, since it uses less digits than its factorization.

66616641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475 (or 1469 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 66616641 is about 8161.9018004384. The cubic root of 66616641 is about 405.3786855892.

The spelling of 66616641 in words is "sixty-six million, six hundred sixteen thousand, six hundred forty-one".