21132021 has 8 divisors (see below), whose sum is σ = 28202944. Its totient is φ = 14074560.

The previous prime is 21132011. The next prime is 21132061. The reversal of 21132021 is 12023112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21132021 - 2⁵ = 21131989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21131988 and 21132006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1176 + ... + 6606.

It is an arithmetic number, because the mean of its divisors is an integer number (3525368).

Almost surely, 2^21132021 is an apocalyptic number.

It is an amenable number.

21132021 is a deficient number, since it is larger than the sum of its proper divisors (7070923).

21132021 is a wasteful number, since it uses less digits than its factorization.

21132021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6731.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21132021 is about 4596.9577983706. The cubic root of 21132021 is about 276.4693625604.

Adding to 21132021 its reverse (12023112), we get a palindrome (33155133).

The spelling of 21132021 in words is "twenty-one million, one hundred thirty-two thousand, twenty-one".