1023565666 has 4 divisors (see below), whose sum is σ = 1535348502. Its totient is φ = 511782832.

The previous prime is 1023565661. The next prime is 1023565667. The reversal of 1023565666 is 6665653201.

It is a happy number.

1023565666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6665653201 = 31 ⋅215021071.

It can be written as a sum of positive squares in only one way, i.e., 698809225 + 324756441 = 26435^2 + 18021^2 .

It is a super-2 number, since 2×1023565666² = 2095373345228047112, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) 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 (1023565661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255891415 + ... + 255891418.

Almost surely, 2^1023565666 is an apocalyptic number.

1023565666 is a deficient number, since it is larger than the sum of its proper divisors (511782836).

1023565666 is an equidigital number, since it uses as much as digits as its factorization.

1023565666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511782835.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 1023565666 is about 31993.2128114699. The cubic root of 1023565666 is about 1007.7943128490.

The spelling of 1023565666 in words is "one billion, twenty-three million, five hundred sixty-five thousand, six hundred sixty-six".