21698827 has 2 divisors, whose sum is σ = 21698828. Its totient is φ = 21698826.

The previous prime is 21698801. The next prime is 21698849. The reversal of 21698827 is 72889612.

21698827 is nontrivially palindromic in base 12.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21698827 - 2¹⁵ = 21666059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21698927) 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, 10849413 + 10849414.

It is an arithmetic number, because the mean of its divisors is an integer number (10849414).

Almost surely, 2^21698827 is an apocalyptic number.

21698827 is a deficient number, since it is larger than the sum of its proper divisors (1).

21698827 is an equidigital number, since it uses as much as digits as its factorization.

21698827 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 21698827 is about 4658.1999742390. The cubic root of 21698827 is about 278.9194193535.

The spelling of 21698827 in words is "twenty-one million, six hundred ninety-eight thousand, eight hundred twenty-seven".