21860543 has 2 divisors, whose sum is σ = 21860544. Its totient is φ = 21860542.

The previous prime is 21860533. The next prime is 21860561. The reversal of 21860543 is 34506812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21860543 - 2⁶ = 21860479 is a prime.

It is equal to p_1380971 and since 21860543 and 1380971 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21860513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10930271 + 10930272.

It is an arithmetic number, because the mean of its divisors is an integer number (10930272).

Almost surely, 2^21860543 is an apocalyptic number.

21860543 is a deficient number, since it is larger than the sum of its proper divisors (1).

21860543 is an equidigital number, since it uses as much as digits as its factorization.

21860543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 21860543 is about 4675.5259597183. The cubic root of 21860543 is about 279.6106109482.

The spelling of 21860543 in words is "twenty-one million, eight hundred sixty thousand, five hundred forty-three".