21544251771 has 8 divisors (see below), whose sum is σ = 32829336064. Its totient is φ = 12311001000.

The previous prime is 21544251761. The next prime is 21544251803. The reversal of 21544251771 is 17715244512.

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

It is not a de Polignac number, because 21544251771 - 2¹⁴ = 21544235387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21544251761) 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, 512958355 + ... + 512958396.

It is an arithmetic number, because the mean of its divisors is an integer number (4103667008).

Almost surely, 2^21544251771 is an apocalyptic number.

21544251771 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21544251771 is a deficient number, since it is larger than the sum of its proper divisors (11285084293).

21544251771 is a wasteful number, since it uses less digits than its factorization.

21544251771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025916761.

The product of its digits is 78400, while the sum is 39.

The spelling of 21544251771 in words is "twenty-one billion, five hundred forty-four million, two hundred fifty-one thousand, seven hundred seventy-one".