66421894 has 16 divisors (see below), whose sum is σ = 124217856. Its totient is φ = 25878600.

The previous prime is 66421837. The next prime is 66421903. The reversal of 66421894 is 49812466.

66421894 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215502 + ... + 215809.

It is an arithmetic number, because the mean of its divisors is an integer number (7763616).

Almost surely, 2^66421894 is an apocalyptic number.

66421894 is a deficient number, since it is larger than the sum of its proper divisors (57795962).

66421894 is a wasteful number, since it uses less digits than its factorization.

66421894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431331.

The product of its digits is 82944, while the sum is 40.

The square root of 66421894 is about 8149.9628220011. The cubic root of 66421894 is about 404.9832721842.

The spelling of 66421894 in words is "sixty-six million, four hundred twenty-one thousand, eight hundred ninety-four".