21068397 has 32 divisors (see below), whose sum is σ = 37555200. Its totient is φ = 11403504.

The previous prime is 21068357. The next prime is 21068417. The reversal of 21068397 is 79386012.

It is not a de Polignac number, because 21068397 - 2¹² = 21064301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21068317) 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 in 31 ways as a sum of consecutive naturals, for example, 658 + ... + 6524.

It is an arithmetic number, because the mean of its divisors is an integer number (1173600).

Almost surely, 2^21068397 is an apocalyptic number.

21068397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21068397 is a deficient number, since it is larger than the sum of its proper divisors (16486803).

21068397 is a wasteful number, since it uses less digits than its factorization.

21068397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5902 (or 5896 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21068397 is about 4590.0323528272. The cubic root of 21068397 is about 276.1916202400.

The spelling of 21068397 in words is "twenty-one million, sixty-eight thousand, three hundred ninety-seven".