66423520 has 24 divisors (see below), whose sum is σ = 156925944. Its totient is φ = 26569344.

The previous prime is 66423509. The next prime is 66423551. The reversal of 66423520 is 2532466.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207414 + ... + 207733.

It is an arithmetic number, because the mean of its divisors is an integer number (6538581).

Almost surely, 2^66423520 is an apocalyptic number.

It is an amenable number.

66423520 is an abundant number, since it is smaller than the sum of its proper divisors (90502424).

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

66423520 is a wasteful number, since it uses less digits than its factorization.

66423520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415162 (or 415154 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 66423520 is about 8150.0625764469. The cubic root of 66423520 is about 404.9865768045.

Adding to 66423520 its reverse (2532466), we get a palindrome (68955986).

The spelling of 66423520 in words is "sixty-six million, four hundred twenty-three thousand, five hundred twenty".