21354393 has 8 divisors (see below), whose sum is σ = 28792800. Its totient is φ = 14076128.

The previous prime is 21354391. The next prime is 21354407. The reversal of 21354393 is 39345312.

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 21354393 - 2¹ = 21354391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21354393.

It is not an unprimeable number, because it can be changed into a prime (21354391) 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, 39723 + ... + 40256.

It is an arithmetic number, because the mean of its divisors is an integer number (3599100).

Almost surely, 2^21354393 is an apocalyptic number.

It is an amenable number.

21354393 is a deficient number, since it is larger than the sum of its proper divisors (7438407).

21354393 is an equidigital number, since it uses as much as digits as its factorization.

21354393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80071.

The product of its digits is 9720, while the sum is 30.

The square root of 21354393 is about 4621.0813669530. The cubic root of 21354393 is about 277.4357419594.

The spelling of 21354393 in words is "twenty-one million, three hundred fifty-four thousand, three hundred ninety-three".