21127959 has 20 divisors (see below), whose sum is σ = 32103720. Its totient is φ = 13843440.

The previous prime is 21127927. The next prime is 21127963. The reversal of 21127959 is 95972112.

It is not a de Polignac number, because 21127959 - 2⁵ = 21127927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21127969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2569 + ... + 6989.

It is an arithmetic number, because the mean of its divisors is an integer number (1605186).

Almost surely, 2^21127959 is an apocalyptic number.

21127959 is a deficient number, since it is larger than the sum of its proper divisors (10975761).

21127959 is an equidigital number, since it uses as much as digits as its factorization.

21127959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4492 (or 4483 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 21127959 is about 4596.5159632052. The cubic root of 21127959 is about 276.4516470989.

The spelling of 21127959 in words is "twenty-one million, one hundred twenty-seven thousand, nine hundred fifty-nine".