21806601 has 8 divisors (see below), whose sum is σ = 29098080. Its totient is φ = 14526432.

The previous prime is 21806593. The next prime is 21806621. The reversal of 21806601 is 10660812.

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

It is not a de Polignac number, because 21806601 - 2³ = 21806593 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21806621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4101 + ... + 7773.

It is an arithmetic number, because the mean of its divisors is an integer number (3637260).

Almost surely, 2^21806601 is an apocalyptic number.

It is an amenable number.

21806601 is a deficient number, since it is larger than the sum of its proper divisors (7291479).

21806601 is a wasteful number, since it uses less digits than its factorization.

21806601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5655.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21806601 is about 4669.7538479025. The cubic root of 21806601 is about 279.3804370617.

The spelling of 21806601 in words is "twenty-one million, eight hundred six thousand, six hundred one".