21561352 has 16 divisors (see below), whose sum is σ = 42555600. Its totient is φ = 10213200.

The previous prime is 21561349. The next prime is 21561359. The reversal of 21561352 is 25316512.

It is not an unprimeable number, because it can be changed into a prime (21561359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70774 + ... + 71077.

It is an arithmetic number, because the mean of its divisors is an integer number (2659725).

Almost surely, 2^21561352 is an apocalyptic number.

It is an amenable number.

21561352 is a deficient number, since it is larger than the sum of its proper divisors (20994248).

21561352 is a wasteful number, since it uses less digits than its factorization.

21561352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141876 (or 141872 counting only the distinct ones).

The product of its digits is 1800, while the sum is 25.

The square root of 21561352 is about 4643.4202911216. The cubic root of 21561352 is about 278.3291307368.

Adding to 21561352 its reverse (25316512), we get a palindrome (46877864).

The spelling of 21561352 in words is "twenty-one million, five hundred sixty-one thousand, three hundred fifty-two".