66213423 has 32 divisors (see below), whose sum is σ = 103833600. Its totient is φ = 41586048.

The previous prime is 66213361. The next prime is 66213431. The reversal of 66213423 is 32431266.

66213423 is a `hidden beast` number, since 6 + 621 + 34 + 2 + 3 = 666.

It is not a de Polignac number, because 66213423 - 2⁹ = 66212911 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66213443) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 172690 + ... + 173072.

It is an arithmetic number, because the mean of its divisors is an integer number (3244800).

Almost surely, 2^66213423 is an apocalyptic number.

66213423 is a deficient number, since it is larger than the sum of its proper divisors (37620177).

66213423 is a wasteful number, since it uses less digits than its factorization.

66213423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748 (or 742 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 66213423 is about 8137.1630805828. The cubic root of 66213423 is about 404.5591361829.

Adding to 66213423 its reverse (32431266), we get a palindrome (98644689).

The spelling of 66213423 in words is "sixty-six million, two hundred thirteen thousand, four hundred twenty-three".