21553240315 has 16 divisors (see below), whose sum is σ = 27368534016. Its totient is φ = 16260613600.

The previous prime is 21553240309. The next prime is 21553240343. The reversal of 21553240315 is 51304235512.

It is not a de Polignac number, because 21553240315 - 2⁷ = 21553240187 is a prime.

It is a super-2 number, since 2×21553240315² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1311691 + ... + 1328020.

It is an arithmetic number, because the mean of its divisors is an integer number (1710533376).

Almost surely, 2^21553240315 is an apocalyptic number.

21553240315 is a deficient number, since it is larger than the sum of its proper divisors (5815293701).

21553240315 is a wasteful number, since it uses less digits than its factorization.

21553240315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2639810.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21553240315 its reverse (51304235512), we get a palindrome (72857475827).

The spelling of 21553240315 in words is "twenty-one billion, five hundred fifty-three million, two hundred forty thousand, three hundred fifteen".