21120252145 has 8 divisors (see below), whose sum is σ = 25385250240. Its totient is φ = 16868903280.

The previous prime is 21120252121. The next prime is 21120252163. The reversal of 21120252145 is 54125202112.

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

It is not a de Polignac number, because 21120252145 - 2⁷ = 21120252017 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3408901 + ... + 3415090.

It is an arithmetic number, because the mean of its divisors is an integer number (3173156280).

Almost surely, 2^21120252145 is an apocalyptic number.

It is an amenable number.

21120252145 is a deficient number, since it is larger than the sum of its proper divisors (4264998095).

21120252145 is an equidigital number, since it uses as much as digits as its factorization.

21120252145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6824615.

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21120252145 its reverse (54125202112), we get a palindrome (75245454257).

The spelling of 21120252145 in words is "twenty-one billion, one hundred twenty million, two hundred fifty-two thousand, one hundred forty-five".