66991450 has 48 divisors (see below), whose sum is σ = 131777280. Its totient is φ = 25296320.

The previous prime is 66991427. The next prime is 66991459. The reversal of 66991450 is 5419966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66991459) 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 23 ways as a sum of consecutive naturals, for example, 67659 + ... + 68641.

It is an arithmetic number, because the mean of its divisors is an integer number (2745360).

Almost surely, 2^66991450 is an apocalyptic number.

66991450 is a deficient number, since it is larger than the sum of its proper divisors (64785830).

66991450 is a wasteful number, since it uses less digits than its factorization.

66991450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071 (or 1066 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 66991450 is about 8184.8304808347. The cubic root of 66991450 is about 406.1375325752.

The spelling of 66991450 in words is "sixty-six million, nine hundred ninety-one thousand, four hundred fifty".