21389001 has 8 divisors (see below), whose sum is σ = 28628160. Its totient is φ = 14204592.

The previous prime is 21388993. The next prime is 21389021. The reversal of 21389001 is 10098312.

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

It is not a de Polignac number, because 21389001 - 2³ = 21388993 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21389021) 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 7 ways as a sum of consecutive naturals, for example, 12766 + ... + 14343.

It is an arithmetic number, because the mean of its divisors is an integer number (3578520).

Almost surely, 2^21389001 is an apocalyptic number.

It is an amenable number.

21389001 is a deficient number, since it is larger than the sum of its proper divisors (7239159).

21389001 is a wasteful number, since it uses less digits than its factorization.

21389001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27375.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21389001 is about 4624.8244291000. The cubic root of 21389001 is about 277.5855364917.

The spelling of 21389001 in words is "twenty-one million, three hundred eighty-nine thousand, one".