21559151 has 8 divisors (see below), whose sum is σ = 22357200. Its totient is φ = 20764800.

The previous prime is 21559141. The next prime is 21559159. The reversal of 21559151 is 15195512.

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 21559151 - 2¹⁴ = 21542767 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21559159) 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, 17351 + ... + 18551.

It is an arithmetic number, because the mean of its divisors is an integer number (2794650).

Almost surely, 2^21559151 is an apocalyptic number.

21559151 is a deficient number, since it is larger than the sum of its proper divisors (798049).

21559151 is a wasteful number, since it uses less digits than its factorization.

21559151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1849.

The product of its digits is 2250, while the sum is 29.

The square root of 21559151 is about 4643.1832830505. The cubic root of 21559151 is about 278.3196597280.

The spelling of 21559151 in words is "twenty-one million, five hundred fifty-nine thousand, one hundred fifty-one".