66643620 has 24 divisors (see below), whose sum is σ = 186602304. Its totient is φ = 17771616.

The previous prime is 66643609. The next prime is 66643637. The reversal of 66643620 is 2634666.

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, 555304 + ... + 555423.

It is an arithmetic number, because the mean of its divisors is an integer number (7775096).

Almost surely, 2^66643620 is an apocalyptic number.

66643620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66643620 is an abundant number, since it is smaller than the sum of its proper divisors (119958684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66643620 is a wasteful number, since it uses less digits than its factorization.

66643620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110739 (or 1110737 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 66643620 is about 8163.5543729432. The cubic root of 66643620 is about 405.4334028256.

The spelling of 66643620 in words is "sixty-six million, six hundred forty-three thousand, six hundred twenty".