21133031 has 4 divisors (see below), whose sum is σ = 21704232. Its totient is φ = 20561832.

The previous prime is 21133027. The next prime is 21133087. The reversal of 21133031 is 13033112.

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 21133031 - 2² = 21133027 is a prime.

It is a super-2 number, since 2×21133031² = 893209998493922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21132997 and 21133015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133631) 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, 285545 + ... + 285618.

It is an arithmetic number, because the mean of its divisors is an integer number (5426058).

Almost surely, 2^21133031 is an apocalyptic number.

21133031 is a deficient number, since it is larger than the sum of its proper divisors (571201).

21133031 is an equidigital number, since it uses as much as digits as its factorization.

21133031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571200.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 21133031 is about 4597.0676523192. The cubic root of 21133031 is about 276.4737670864.

Adding to 21133031 its reverse (13033112), we get a palindrome (34166143).

The spelling of 21133031 in words is "twenty-one million, one hundred thirty-three thousand, thirty-one".