123220665 has 48 divisors (see below), whose sum is σ = 218282688. Its totient is φ = 64291968.

The previous prime is 123220663. The next prime is 123220667. The reversal of 123220665 is 566022321.

It is an interprime number because it is at equal distance from previous prime (123220663) and next prime (123220667).

It is not a de Polignac number, because 123220665 - 2¹ = 123220663 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (123220661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 755874 + ... + 756036.

It is an arithmetic number, because the mean of its divisors is an integer number (4547556).

Almost surely, 2^123220665 is an apocalyptic number.

123220665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

123220665 is a deficient number, since it is larger than the sum of its proper divisors (95062023).

123220665 is a wasteful number, since it uses less digits than its factorization.

123220665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 123220665 is about 11100.4803950099. The cubic root of 123220665 is about 497.6162064511.

Adding to 123220665 its reverse (566022321), we get a palindrome (689242986).

The spelling of 123220665 in words is "one hundred twenty-three million, two hundred twenty thousand, six hundred sixty-five".