23215666 has 4 divisors (see below), whose sum is σ = 34823502. Its totient is φ = 11607832.

The previous prime is 23215597. The next prime is 23215667. The reversal of 23215666 is 66651232.

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

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 6610041 = 4075^2 + 2571^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (23215667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5803915 + ... + 5803918.

Almost surely, 2^23215666 is an apocalyptic number.

23215666 is a deficient number, since it is larger than the sum of its proper divisors (11607836).

23215666 is a wasteful number, since it uses less digits than its factorization.

23215666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11607835.

The product of its digits is 12960, while the sum is 31.

The square root of 23215666 is about 4818.2637951860. The cubic root of 23215666 is about 285.2728115127.

Adding to 23215666 its reverse (66651232), we get a palindrome (89866898).

The spelling of 23215666 in words is "twenty-three million, two hundred fifteen thousand, six hundred sixty-six".