21100559 has 2 divisors, whose sum is σ = 21100560. Its totient is φ = 21100558.

The previous prime is 21100543. The next prime is 21100579. The reversal of 21100559 is 95500112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21100559 - 2⁴ = 21100543 is a prime.

It is a super-2 number, since 2×21100559² = 890467180224962, 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 (21100529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550279 + 10550280.

It is an arithmetic number, because the mean of its divisors is an integer number (10550280).

Almost surely, 2^21100559 is an apocalyptic number.

21100559 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100559 is an equidigital number, since it uses as much as digits as its factorization.

21100559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 21100559 is about 4593.5344779374. The cubic root of 21100559 is about 276.3320890610.

The spelling of 21100559 in words is "twenty-one million, one hundred thousand, five hundred fifty-nine".