21498847 has 2 divisors, whose sum is σ = 21498848. Its totient is φ = 21498846.

The previous prime is 21498817. The next prime is 21498857. The reversal of 21498847 is 74889412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21498847 - 2¹⁵ = 21466079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21498817) 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, 10749423 + 10749424.

It is an arithmetic number, because the mean of its divisors is an integer number (10749424).

Almost surely, 2^21498847 is an apocalyptic number.

21498847 is a deficient number, since it is larger than the sum of its proper divisors (1).

21498847 is an equidigital number, since it uses as much as digits as its factorization.

21498847 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 43.

The square root of 21498847 is about 4636.6849148934. The cubic root of 21498847 is about 278.0599175579.

The spelling of 21498847 in words is "twenty-one million, four hundred ninety-eight thousand, eight hundred forty-seven".