21559013 has 8 divisors (see below), whose sum is σ = 25056960. Its totient is φ = 18165600.

The previous prime is 21558997. The next prime is 21559019. The reversal of 21559013 is 31095512.

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 21559013 - 2⁴ = 21558997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21559019) 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, 25688 + ... + 26513.

It is an arithmetic number, because the mean of its divisors is an integer number (3132120).

Almost surely, 2^21559013 is an apocalyptic number.

It is an amenable number.

21559013 is a deficient number, since it is larger than the sum of its proper divisors (3497947).

21559013 is an equidigital number, since it uses as much as digits as its factorization.

21559013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52267.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 21559013 is about 4643.1684225322. The cubic root of 21559013 is about 278.3190658859.

The spelling of 21559013 in words is "twenty-one million, five hundred fifty-nine thousand, thirteen".