21552043 has 2 divisors, whose sum is σ = 21552044. Its totient is φ = 21552042.

The previous prime is 21552031. The next prime is 21552053. The reversal of 21552043 is 34025512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21552043 - 2²¹ = 19454891 is a prime.

It is not a weakly prime, because it can be changed into another prime (21552053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776021 + 10776022.

It is an arithmetic number, because the mean of its divisors is an integer number (10776022).

Almost surely, 2^21552043 is an apocalyptic number.

21552043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552043 is an equidigital number, since it uses as much as digits as its factorization.

21552043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21552043 is about 4642.4177967951. The cubic root of 21552043 is about 278.2890692594.

Adding to 21552043 its reverse (34025512), we get a palindrome (55577555).

The spelling of 21552043 in words is "twenty-one million, five hundred fifty-two thousand, forty-three".