21559047 has 8 divisors (see below), whose sum is σ = 29216880. Its totient is φ = 14136960.

The previous prime is 21559037. The next prime is 21559061. The reversal of 21559047 is 74095512.

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

It is not a de Polignac number, because 21559047 - 2¹¹ = 21556999 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21558999 and 21559017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21559037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58722 + ... + 59087.

It is an arithmetic number, because the mean of its divisors is an integer number (3652110).

Almost surely, 2^21559047 is an apocalyptic number.

21559047 is a deficient number, since it is larger than the sum of its proper divisors (7657833).

21559047 is a wasteful number, since it uses less digits than its factorization.

21559047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117873.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 21559047 is about 4643.1720838237. The cubic root of 21559047 is about 278.3192121951.

The spelling of 21559047 in words is "twenty-one million, five hundred fifty-nine thousand, forty-seven".