21398201 has 8 divisors (see below), whose sum is σ = 24148800. Its totient is φ = 18781840.

The previous prime is 21398191. The next prime is 21398227. The reversal of 21398201 is 10289312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21398201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21398261) 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 in 7 ways as a sum of consecutive naturals, for example, 33221 + ... + 33858.

It is an arithmetic number, because the mean of its divisors is an integer number (3018600).

Almost surely, 2^21398201 is an apocalyptic number.

It is an amenable number.

21398201 is a deficient number, since it is larger than the sum of its proper divisors (2750599).

21398201 is a wasteful number, since it uses less digits than its factorization.

21398201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67119.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21398201 is about 4625.8189545204. The cubic root of 21398201 is about 277.6253298552.

Subtracting from 21398201 its reverse (10289312), we obtain a square (11108889 = 3333²).

The spelling of 21398201 in words is "twenty-one million, three hundred ninety-eight thousand, two hundred one".