2159521 has 16 divisors (see below), whose sum is σ = 2800000. Its totient is φ = 1617408.

The previous prime is 2159519. The next prime is 2159533. The reversal of 2159521 is 1259512.

It is not a de Polignac number, because 2159521 - 2¹ = 2159519 is a prime.

It is a super-3 number, since 3×2159521³ = 30212979058403333283, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2159501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1105 + ... + 2353.

It is an arithmetic number, because the mean of its divisors is an integer number (175000).

2^2159521 is an apocalyptic number.

It is an amenable number.

2159521 is a deficient number, since it is larger than the sum of its proper divisors (640479).

2159521 is a wasteful number, since it uses less digits than its factorization.

2159521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1288.

The product of its digits is 900, while the sum is 25.

The square root of 2159521 is about 1469.5308775252. The cubic root of 2159521 is about 129.2565253787.

Subtracting from 2159521 its reverse (1259512), we obtain a palindrome (900009).

The spelling of 2159521 in words is "two million, one hundred fifty-nine thousand, five hundred twenty-one".