21770609 has 8 divisors (see below), whose sum is σ = 24961728. Its totient is φ = 18599760.

The previous prime is 21770603. The next prime is 21770611. The reversal of 21770609 is 90607712.

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

It is a cyclic number.

It is not a de Polignac number, because 21770609 - 2¹² = 21766513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21770603) 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, 2687 + ... + 7124.

It is an arithmetic number, because the mean of its divisors is an integer number (3120216).

Almost surely, 2^21770609 is an apocalyptic number.

It is an amenable number.

21770609 is a deficient number, since it is larger than the sum of its proper divisors (3191119).

21770609 is an equidigital number, since it uses as much as digits as its factorization.

21770609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10135.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 21770609 is about 4665.8985201138. The cubic root of 21770609 is about 279.2266457398.

The spelling of 21770609 in words is "twenty-one million, seven hundred seventy thousand, six hundred nine".