21886541 has 2 divisors, whose sum is σ = 21886542. Its totient is φ = 21886540.

The previous prime is 21886517. The next prime is 21886549. The reversal of 21886541 is 14568812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21353641 + 532900 = 4621^2 + 730^2 .

It is a cyclic number.

It is not a de Polignac number, because 21886541 - 2⁶ = 21886477 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21886549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10943270 + 10943271.

It is an arithmetic number, because the mean of its divisors is an integer number (10943271).

Almost surely, 2^21886541 is an apocalyptic number.

It is an amenable number.

21886541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21886541 is an equidigital number, since it uses as much as digits as its factorization.

21886541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15360, while the sum is 35.

The square root of 21886541 is about 4678.3053555748. The cubic root of 21886541 is about 279.7214108317.

The spelling of 21886541 in words is "twenty-one million, eight hundred eighty-six thousand, five hundred forty-one".