213506666 has 8 divisors (see below), whose sum is σ = 321671520. Its totient is φ = 106282828.

The previous prime is 213506659. The next prime is 213506669. The reversal of 213506666 is 666605312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (213506669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234686 + ... + 235593.

It is an arithmetic number, because the mean of its divisors is an integer number (40208940).

Almost surely, 2^213506666 is an apocalyptic number.

213506666 is a deficient number, since it is larger than the sum of its proper divisors (108164854).

213506666 is a wasteful number, since it uses less digits than its factorization.

213506666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470508.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 213506666 is about 14611.8673002461. The cubic root of 213506666 is about 597.6824169482.

The spelling of 213506666 in words is "two hundred thirteen million, five hundred six thousand, six hundred sixty-six".