21934421 has 8 divisors (see below), whose sum is σ = 22494240. Its totient is φ = 21380112.

The previous prime is 21934399. The next prime is 21934427. The reversal of 21934421 is 12443912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21934421 - 2⁶ = 21934357 is a prime.

It is a super-2 number, since 2×21934421² = 962237649210482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7370 + ... + 9908.

It is an arithmetic number, because the mean of its divisors is an integer number (2811780).

Almost surely, 2^21934421 is an apocalyptic number.

It is an amenable number.

21934421 is a deficient number, since it is larger than the sum of its proper divisors (559819).

21934421 is a wasteful number, since it uses less digits than its factorization.

21934421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2755.

The product of its digits is 1728, while the sum is 26.

The square root of 21934421 is about 4683.4197975411. The cubic root of 21934421 is about 279.9252393943.

The spelling of 21934421 in words is "twenty-one million, nine hundred thirty-four thousand, four hundred twenty-one".