21934031 has 4 divisors (see below), whose sum is σ = 25067472. Its totient is φ = 18800592.

The previous prime is 21934013. The next prime is 21934039. The reversal of 21934031 is 13043912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21934031 is a prime.

It is a super-2 number, since 2×21934031² = 962203431817922, 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 = 21933988 and 21934006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1566710 + ... + 1566723.

It is an arithmetic number, because the mean of its divisors is an integer number (6266868).

Almost surely, 2^21934031 is an apocalyptic number.

21934031 is a deficient number, since it is larger than the sum of its proper divisors (3133441).

21934031 is an equidigital number, since it uses as much as digits as its factorization.

21934031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3133440.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 21934031 is about 4683.3781611140. The cubic root of 21934031 is about 279.9235803354.

Adding to 21934031 its reverse (13043912), we get a palindrome (34977943).

The spelling of 21934031 in words is "twenty-one million, nine hundred thirty-four thousand, thirty-one".