66212219 has 4 divisors (see below), whose sum is σ = 67334520. Its totient is φ = 65089920.

The previous prime is 66212213. The next prime is 66212227. The reversal of 66212219 is 91221266.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66212219 - 2¹² = 66208123 is a prime.

It is a super-2 number, since 2×66212219² = 8768115889807922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66212191 and 66212200.

It is not an unprimeable number, because it can be changed into a prime (66212213) 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, 561062 + ... + 561179.

It is an arithmetic number, because the mean of its divisors is an integer number (16833630).

Almost surely, 2^66212219 is an apocalyptic number.

66212219 is a deficient number, since it is larger than the sum of its proper divisors (1122301).

66212219 is a wasteful number, since it uses less digits than its factorization.

66212219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122300.

The product of its digits is 2592, while the sum is 29.

The square root of 66212219 is about 8137.0890986888. The cubic root of 66212219 is about 404.5566840509.

The spelling of 66212219 in words is "sixty-six million, two hundred twelve thousand, two hundred nineteen".