21618794 has 8 divisors (see below), whose sum is σ = 32522688. Its totient is φ = 10777900.

The previous prime is 21618787. The next prime is 21618803. The reversal of 21618794 is 49781612.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14882 + ... + 16269.

It is an arithmetic number, because the mean of its divisors is an integer number (4065336).

Almost surely, 2^21618794 is an apocalyptic number.

21618794 is a deficient number, since it is larger than the sum of its proper divisors (10903894).

21618794 is a wasteful number, since it uses less digits than its factorization.

21618794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31500.

The product of its digits is 24192, while the sum is 38.

The square root of 21618794 is about 4649.6014882998. The cubic root of 21618794 is about 278.5760788429.

It can be divided in two parts, 216 and 18794, that multiplied together give a palindrome (4059504).

The spelling of 21618794 in words is "twenty-one million, six hundred eighteen thousand, seven hundred ninety-four".