21071927 has 2 divisors, whose sum is σ = 21071928. Its totient is φ = 21071926.

The previous prime is 21071917. The next prime is 21071977. The reversal of 21071927 is 72917012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21071927 - 2⁶ = 21071863 is a prime.

It is a super-2 number, since 2×21071927² = 888052214986658, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21071927.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21071917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535963 + 10535964.

It is an arithmetic number, because the mean of its divisors is an integer number (10535964).

Almost surely, 2^21071927 is an apocalyptic number.

21071927 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071927 is an equidigital number, since it uses as much as digits as its factorization.

21071927 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21071927 is about 4590.4168656016. The cubic root of 21071927 is about 276.2070446372.

Adding to 21071927 its reverse (72917012), we get a palindrome (93988939).

The spelling of 21071927 in words is "twenty-one million, seventy-one thousand, nine hundred twenty-seven".