21755316551 has 8 divisors (see below), whose sum is σ = 23293863360. Its totient is φ = 20245527808.

The previous prime is 21755316533. The next prime is 21755316553. The reversal of 21755316551 is 15561355712.

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

It is a cyclic number.

It is not a de Polignac number, because 21755316551 - 2²⁶ = 21688207687 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21755316499 and 21755316508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755316553) 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, 7187951 + ... + 7190976.

It is an arithmetic number, because the mean of its divisors is an integer number (2911732920).

Almost surely, 2^21755316551 is an apocalyptic number.

21755316551 is a deficient number, since it is larger than the sum of its proper divisors (1538546809).

21755316551 is a wasteful number, since it uses less digits than its factorization.

21755316551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14379033.

The product of its digits is 157500, while the sum is 41.

The spelling of 21755316551 in words is "twenty-one billion, seven hundred fifty-five million, three hundred sixteen thousand, five hundred fifty-one".