21014639 has 2 divisors, whose sum is σ = 21014640. Its totient is φ = 21014638.

The previous prime is 21014629. The next prime is 21014641. The reversal of 21014639 is 93641012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21014639 - 2¹² = 21010543 is a prime.

Together with 21014641, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21014629) 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 as a sum of consecutive naturals, namely, 10507319 + 10507320.

It is an arithmetic number, because the mean of its divisors is an integer number (10507320).

Almost surely, 2^21014639 is an apocalyptic number.

21014639 is a deficient number, since it is larger than the sum of its proper divisors (1).

21014639 is an equidigital number, since it uses as much as digits as its factorization.

21014639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21014639 is about 4584.1726625423. The cubic root of 21014639 is about 275.9565105110.

The spelling of 21014639 in words is "twenty-one million, fourteen thousand, six hundred thirty-nine".