21844351 has 2 divisors, whose sum is σ = 21844352. Its totient is φ = 21844350.

The previous prime is 21844313. The next prime is 21844379. The reversal of 21844351 is 15344812.

It is an a-pointer prime, because the next prime (21844379) can be obtained adding 21844351 to its sum of digits (28).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21844351 - 2⁷ = 21844223 is a prime.

It is a super-2 number, since 2×21844351² = 954351341222402, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21844051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922175 + 10922176.

It is an arithmetic number, because the mean of its divisors is an integer number (10922176).

Almost surely, 2^21844351 is an apocalyptic number.

21844351 is a deficient number, since it is larger than the sum of its proper divisors (1).

21844351 is an equidigital number, since it uses as much as digits as its factorization.

21844351 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 28.

The square root of 21844351 is about 4673.7940690621. The cubic root of 21844351 is about 279.5415584809.

The spelling of 21844351 in words is "twenty-one million, eight hundred forty-four thousand, three hundred fifty-one".