21293318 has 8 divisors (see below), whose sum is σ = 32325048. Its totient is φ = 10518304.

The previous prime is 21293317. The next prime is 21293329. The reversal of 21293318 is 81339212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21293317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63971 + ... + 64302.

It is an arithmetic number, because the mean of its divisors is an integer number (4040631).

Almost surely, 2^21293318 is an apocalyptic number.

21293318 is a deficient number, since it is larger than the sum of its proper divisors (11031730).

21293318 is a wasteful number, since it uses less digits than its factorization.

21293318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128358.

The product of its digits is 2592, while the sum is 29.

The square root of 21293318 is about 4614.4683334053. The cubic root of 21293318 is about 277.1709944406.

The spelling of 21293318 in words is "twenty-one million, two hundred ninety-three thousand, three hundred eighteen".