21152344551 has 8 divisors (see below), whose sum is σ = 30372597360. Its totient is φ = 13016827392.

The previous prime is 21152344517. The next prime is 21152344553. The reversal of 21152344551 is 15544325112.

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

It is not a de Polignac number, because 21152344551 - 2¹⁷ = 21152213479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152344553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271183866 + ... + 271183943.

It is an arithmetic number, because the mean of its divisors is an integer number (3796574670).

Almost surely, 2^21152344551 is an apocalyptic number.

21152344551 is a deficient number, since it is larger than the sum of its proper divisors (9220252809).

21152344551 is a wasteful number, since it uses less digits than its factorization.

21152344551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542367825.

The product of its digits is 24000, while the sum is 33.

Adding to 21152344551 its reverse (15544325112), we get a palindrome (36696669663).

The spelling of 21152344551 in words is "twenty-one billion, one hundred fifty-two million, three hundred forty-four thousand, five hundred fifty-one".