21214031 has 4 divisors (see below), whose sum is σ = 21561864. Its totient is φ = 20866200.

The previous prime is 21214021. The next prime is 21214049. The reversal of 21214031 is 13041212.

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 21214031 - 2²² = 17019727 is a prime.

It is a super-2 number, since 2×21214031² = 900070222537922, 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 = 21213997 and 21214015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214001) 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, 173825 + ... + 173946.

It is an arithmetic number, because the mean of its divisors is an integer number (5390466).

Almost surely, 2^21214031 is an apocalyptic number.

21214031 is a deficient number, since it is larger than the sum of its proper divisors (347833).

21214031 is an equidigital number, since it uses as much as digits as its factorization.

21214031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347832.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21214031 is about 4605.8691905003. The cubic root of 21214031 is about 276.8265453885.

Adding to 21214031 its reverse (13041212), we get a palindrome (34255243).

The spelling of 21214031 in words is "twenty-one million, two hundred fourteen thousand, thirty-one".