66305640 has 64 divisors (see below), whose sum is σ = 199454400. Its totient is φ = 17633792.

The previous prime is 66305639. The next prime is 66305677. The reversal of 66305640 is 4650366.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 66305598 and 66305607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 81556 + ... + 82364.

It is an arithmetic number, because the mean of its divisors is an integer number (3116475).

Almost surely, 2^66305640 is an apocalyptic number.

66305640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66305640 is an abundant number, since it is smaller than the sum of its proper divisors (133148760).

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

66305640 is a wasteful number, since it uses less digits than its factorization.

66305640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1506 (or 1502 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 66305640 is about 8142.8275187431. The cubic root of 66305640 is about 404.7468620850.

The spelling of 66305640 in words is "sixty-six million, three hundred five thousand, six hundred forty".