21394793 has 4 divisors (see below), whose sum is σ = 24451200. Its totient is φ = 18338388.

The previous prime is 21394781. The next prime is 21394819. The reversal of 21394793 is 39749312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21394793 - 2⁴ = 21394777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21394733) 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 3 ways as a sum of consecutive naturals, for example, 1528193 + ... + 1528206.

It is an arithmetic number, because the mean of its divisors is an integer number (6112800).

Almost surely, 2^21394793 is an apocalyptic number.

It is an amenable number.

21394793 is a deficient number, since it is larger than the sum of its proper divisors (3056407).

21394793 is an equidigital number, since it uses as much as digits as its factorization.

21394793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3056406.

The product of its digits is 40824, while the sum is 38.

The square root of 21394793 is about 4625.4505726470. The cubic root of 21394793 is about 277.6105903395.

The spelling of 21394793 in words is "twenty-one million, three hundred ninety-four thousand, seven hundred ninety-three".