21240346 has 8 divisors (see below), whose sum is σ = 32027904. Its totient is φ = 10564380.

The previous prime is 21240313. The next prime is 21240377. The reversal of 21240346 is 64304212.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27420 + ... + 28183.

It is an arithmetic number, because the mean of its divisors is an integer number (4003488).

Almost surely, 2^21240346 is an apocalyptic number.

21240346 is a deficient number, since it is larger than the sum of its proper divisors (10787558).

21240346 is a wasteful number, since it uses less digits than its factorization.

21240346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55796.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21240346 is about 4608.7249863710. The cubic root of 21240346 is about 276.9409614953.

Adding to 21240346 its reverse (64304212), we get a palindrome (85544558).

The spelling of 21240346 in words is "twenty-one million, two hundred forty thousand, three hundred forty-six".