21552943 has 2 divisors, whose sum is σ = 21552944. Its totient is φ = 21552942.

The previous prime is 21552919. The next prime is 21552983. The reversal of 21552943 is 34925512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21552943 - 2⁵ = 21552911 is a prime.

It is a super-2 number, since 2×21552943² = 929058703922498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21552913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776471 + 10776472.

It is an arithmetic number, because the mean of its divisors is an integer number (10776472).

Almost surely, 2^21552943 is an apocalyptic number.

21552943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552943 is an equidigital number, since it uses as much as digits as its factorization.

21552943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 31.

The square root of 21552943 is about 4642.5147280326. The cubic root of 21552943 is about 278.2929429321.

The spelling of 21552943 in words is "twenty-one million, five hundred fifty-two thousand, nine hundred forty-three".