66813250 has 64 divisors (see below), whose sum is σ = 145177344. Its totient is φ = 22550400.

The previous prime is 66813233. The next prime is 66813251. The reversal of 66813250 is 5231866.

It is not an unprimeable number, because it can be changed into a prime (66813251) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 127489 + ... + 128011.

It is an arithmetic number, because the mean of its divisors is an integer number (2268396).

Almost surely, 2^66813250 is an apocalyptic number.

66813250 is an abundant number, since it is smaller than the sum of its proper divisors (78364094).

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

66813250 is a wasteful number, since it uses less digits than its factorization.

66813250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 66813250 is about 8173.9372397884. The cubic root of 66813250 is about 405.7770986409. Note that the first 3 decimals are identical.

The spelling of 66813250 in words is "sixty-six million, eight hundred thirteen thousand, two hundred fifty".