21152531551 has 8 divisors (see below), whose sum is σ = 21298860000. Its totient is φ = 21006261600.

The previous prime is 21152531479. The next prime is 21152531579. The reversal of 21152531551 is 15513525112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21152531551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152531251) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 912201 + ... + 935101.

It is an arithmetic number, because the mean of its divisors is an integer number (2662357500).

Almost surely, 2^21152531551 is an apocalyptic number.

21152531551 is a deficient number, since it is larger than the sum of its proper divisors (146328449).

21152531551 is a wasteful number, since it uses less digits than its factorization.

21152531551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29249.

The product of its digits is 7500, while the sum is 31.

The spelling of 21152531551 in words is "twenty-one billion, one hundred fifty-two million, five hundred thirty-one thousand, five hundred fifty-one".