21216352024025 has 6 divisors (see below), whose sum is σ = 26308276509822. Its totient is φ = 16973081619200.

The previous prime is 21216352024001. The next prime is 21216352024033. The reversal of 21216352024025 is 52042025361212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3401781849664 + 17814570174361 = 1844392^2 + 4220731^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21216352024025 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 424327040456 + ... + 424327040505.

It is an arithmetic number, because the mean of its divisors is an integer number (4384712751637).

Almost surely, 2^{21216352024025} is an apocalyptic number.

21216352024025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21216352024025 is a deficient number, since it is larger than the sum of its proper divisors (5091924485797).

21216352024025 is an equidigital number, since it uses as much as digits as its factorization.

21216352024025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 848654080971 (or 848654080966 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 21216352024025 its reverse (52042025361212), we get a palindrome (73258377385237).

The spelling of 21216352024025 in words is "twenty-one trillion, two hundred sixteen billion, three hundred fifty-two million, twenty-four thousand, twenty-five".