21088747 has 2 divisors, whose sum is σ = 21088748. Its totient is φ = 21088746.

The previous prime is 21088741. The next prime is 21088763. The reversal of 21088747 is 74788012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21088747 - 2¹⁹ = 20564459 is a prime.

It is not a weakly prime, because it can be changed into another prime (21088741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10544373 + 10544374.

It is an arithmetic number, because the mean of its divisors is an integer number (10544374).

Almost surely, 2^21088747 is an apocalyptic number.

21088747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21088747 is an equidigital number, since it uses as much as digits as its factorization.

21088747 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 21088747 is about 4592.2485777667. The cubic root of 21088747 is about 276.2805162742.

The spelling of 21088747 in words is "twenty-one million, eighty-eight thousand, seven hundred forty-seven".