21332131 has 4 divisors (see below), whose sum is σ = 21363264. Its totient is φ = 21301000.

The previous prime is 21332119. The next prime is 21332141. The reversal of 21332131 is 13123312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21332131 - 2¹¹ = 21330083 is a prime.

It is a super-2 number, since 2×21332131² = 910119626002322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21332141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14515 + ... + 15916.

It is an arithmetic number, because the mean of its divisors is an integer number (5340816).

Almost surely, 2^21332131 is an apocalyptic number.

21332131 is a deficient number, since it is larger than the sum of its proper divisors (31133).

21332131 is an equidigital number, since it uses as much as digits as its factorization.

21332131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31132.

The product of its digits is 108, while the sum is 16.

The square root of 21332131 is about 4618.6719952818. The cubic root of 21332131 is about 277.3392993213.

Adding to 21332131 its reverse (13123312), we get a palindrome (34455443).

The spelling of 21332131 in words is "twenty-one million, three hundred thirty-two thousand, one hundred thirty-one".