21840707 has 8 divisors (see below), whose sum is σ = 25020000. Its totient is φ = 18676224.

The previous prime is 21840691. The next prime is 21840743. The reversal of 21840707 is 70704812.

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

It is not a de Polignac number, because 21840707 - 2⁴ = 21840691 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21840707.

It is not an unprimeable number, because it can be changed into a prime (21840757) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 332 + ... + 6617.

It is an arithmetic number, because the mean of its divisors is an integer number (3127500).

Almost surely, 2^21840707 is an apocalyptic number.

21840707 is a deficient number, since it is larger than the sum of its proper divisors (3179293).

21840707 is an equidigital number, since it uses as much as digits as its factorization.

21840707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7405.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 21840707 is about 4673.4042196241. The cubic root of 21840707 is about 279.5260135606.

The spelling of 21840707 in words is "twenty-one million, eight hundred forty thousand, seven hundred seven".