21132001 has 16 divisors (see below), whose sum is σ = 23882688. Its totient is φ = 18532800.

The previous prime is 21131989. The next prime is 21132011. The reversal of 21132001 is 10023112.

It is not a de Polignac number, because 21132001 - 2⁹ = 21131489 is a prime.

It is a super-2 number, since 2×21132001² = 893122932528002, which contains 22 as substring.

It is a Duffinian 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 (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38791 + ... + 39331.

It is an arithmetic number, because the mean of its divisors is an integer number (1492668).

Almost surely, 2^21132001 is an apocalyptic number.

It is an amenable number.

21132001 is a deficient number, since it is larger than the sum of its proper divisors (2750687).

21132001 is a wasteful number, since it uses less digits than its factorization.

21132001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21132001 is about 4596.9556230183. The cubic root of 21132001 is about 276.4692753406.

Adding to 21132001 its reverse (10023112), we get a palindrome (31155113).

Subtracting from 21132001 its reverse (10023112), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2113 and 2001, that added together give a palindrome (4114).

The spelling of 21132001 in words is "twenty-one million, one hundred thirty-two thousand, one".