1023213665 has 4 divisors (see below), whose sum is σ = 1227856404. Its totient is φ = 818570928.

The previous prime is 1023213649. The next prime is 1023213689. The reversal of 1023213665 is 5663123201.

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

It can be written as a sum of positive squares in 2 ways, for example, as 596873761 + 426339904 = 24431^2 + 20648^2 .

It is a cyclic number.

It is not a de Polignac number, because 1023213665 - 2⁴ = 1023213649 is a prime.

It is a Duffinian 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, 102321362 + ... + 102321371.

It is an arithmetic number, because the mean of its divisors is an integer number (306964101).

Almost surely, 2^1023213665 is an apocalyptic number.

It is an amenable number.

1023213665 is a deficient number, since it is larger than the sum of its proper divisors (204642739).

1023213665 is an equidigital number, since it uses as much as digits as its factorization.

1023213665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204642738.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 1023213665 is about 31987.7111560049. The cubic root of 1023213665 is about 1007.6787738430.

Adding to 1023213665 its reverse (5663123201), we get a palindrome (6686336866).

The spelling of 1023213665 in words is "one billion, twenty-three million, two hundred thirteen thousand, six hundred sixty-five".