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 2k-21554159 is a prime.
It is a Duffinian number.
It is a congruent number.
Almost surely, 221554159 is an apocalyptic number.
21554159 is a wasteful number, since it uses less digits than its factorization.
21554159 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 10461.
The square root of 21554159 is about 4642.6456896903. The cubic root of 21554159 is about 278.2981765229.
The spelling of 21554159 in words is "twenty-one million, five hundred fifty-four thousand, one hundred fifty-nine".