21323023145 has 8 divisors (see below), whose sum is σ = 25588416456. Its totient is φ = 17057892736.

The previous prime is 21323023097. The next prime is 21323023147. The reversal of 21323023145 is 54132032312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6318978064 + 15004045081 = 79492^2 + 122491^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21323023145 - 2¹² = 21323019049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21323023147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254999 + ... + 328131.

It is an arithmetic number, because the mean of its divisors is an integer number (3198552057).

Almost surely, 2^21323023145 is an apocalyptic number.

It is an amenable number.

21323023145 is a deficient number, since it is larger than the sum of its proper divisors (4265393311).

21323023145 is an equidigital number, since it uses as much as digits as its factorization.

21323023145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131451.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 21323023145 its reverse (54132032312), we get a palindrome (75455055457).

The spelling of 21323023145 in words is "twenty-one billion, three hundred twenty-three million, twenty-three thousand, one hundred forty-five".