21133001 has 4 divisors (see below), whose sum is σ = 21177600. Its totient is φ = 21088404.

The previous prime is 21132983. The next prime is 21133003. The reversal of 21133001 is 10033112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21133001 - 2¹⁰ = 21131977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21133003) 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, 21581 + ... + 22538.

It is an arithmetic number, because the mean of its divisors is an integer number (5294400).

Almost surely, 2^21133001 is an apocalyptic number.

It is an amenable number.

21133001 is a deficient number, since it is larger than the sum of its proper divisors (44599).

21133001 is an equidigital number, since it uses as much as digits as its factorization.

21133001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44598.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 21133001 is about 4597.0643893685. The cubic root of 21133001 is about 276.4736362609.

Adding to 21133001 its reverse (10033112), we get a palindrome (31166113).

The spelling of 21133001 in words is "twenty-one million, one hundred thirty-three thousand, one".