21398003 has 12 divisors (see below), whose sum is σ = 23796360. Its totient is φ = 19224480.

The previous prime is 21397997. The next prime is 21398017. The reversal of 21398003 is 30089312.

It is a de Polignac number, because none of the positive numbers 2^k-21398003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21398033) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9776 + ... + 11762.

It is an arithmetic number, because the mean of its divisors is an integer number (1983030).

Almost surely, 2^21398003 is an apocalyptic number.

21398003 is a deficient number, since it is larger than the sum of its proper divisors (2398357).

21398003 is a wasteful number, since it uses less digits than its factorization.

21398003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2098 (or 2087 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21398003 is about 4625.7975528551. The cubic root of 21398003 is about 277.6244735529.

The spelling of 21398003 in words is "twenty-one million, three hundred ninety-eight thousand, three".