21394403 has 8 divisors (see below), whose sum is σ = 21956400. Its totient is φ = 20839168.

The previous prime is 21394379. The next prime is 21394427. The reversal of 21394403 is 30449312.

It is an interprime number because it is at equal distance from previous prime (21394379) and next prime (21394427).

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

It is a cyclic number.

It is not a de Polignac number, because 21394403 - 2⁶ = 21394339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21394453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5063 + ... + 8271.

It is an arithmetic number, because the mean of its divisors is an integer number (2744550).

Almost surely, 2^21394403 is an apocalyptic number.

21394403 is a deficient number, since it is larger than the sum of its proper divisors (561997).

21394403 is a wasteful number, since it uses less digits than its factorization.

21394403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3381.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21394403 is about 4625.4084143997. The cubic root of 21394403 is about 277.6089034993.

The spelling of 21394403 in words is "twenty-one million, three hundred ninety-four thousand, four hundred three".