21556201 has 8 divisors (see below), whose sum is σ = 22597344. Its totient is φ = 20539680.

The previous prime is 21556159. The next prime is 21556211. The reversal of 21556201 is 10265512.

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 21556201 - 2⁹ = 21555689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21556211) 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, 4351 + ... + 7876.

It is an arithmetic number, because the mean of its divisors is an integer number (2824668).

Almost surely, 2^21556201 is an apocalyptic number.

It is an amenable number.

21556201 is a deficient number, since it is larger than the sum of its proper divisors (1041143).

21556201 is a wasteful number, since it uses less digits than its factorization.

21556201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12311.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 21556201 is about 4642.8656021901. The cubic root of 21556201 is about 278.3069647252.

The spelling of 21556201 in words is "twenty-one million, five hundred fifty-six thousand, two hundred one".