66212420 has 24 divisors (see below), whose sum is σ = 140724864. Its totient is φ = 26165216.

The previous prime is 66212413. The next prime is 66212429. The reversal of 66212420 is 2421266.

It is not an unprimeable number, because it can be changed into a prime (66212429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18284 + ... + 21603.

It is an arithmetic number, because the mean of its divisors is an integer number (5863536).

Almost surely, 2^66212420 is an apocalyptic number.

It is an amenable number.

66212420 is an abundant number, since it is smaller than the sum of its proper divisors (74512444).

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

66212420 is a wasteful number, since it uses less digits than its factorization.

66212420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39979 (or 39977 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 66212420 is about 8137.1014495335. The cubic root of 66212420 is about 404.5570934205.

Adding to 66212420 its reverse (2421266), we get a palindrome (68633686).

The spelling of 66212420 in words is "sixty-six million, two hundred twelve thousand, four hundred twenty".