21711361 has 6 divisors (see below), whose sum is σ = 25256130. Its totient is φ = 18609696.

The previous prime is 21711331. The next prime is 21711419. The reversal of 21711361 is 16311712.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 1640961 = 4480^2 + 1281^2 .

It is not a de Polignac number, because 21711361 - 2⁹ = 21710849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21711301) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 221496 + ... + 221593.

It is an arithmetic number, because the mean of its divisors is an integer number (4209355).

Almost surely, 2^21711361 is an apocalyptic number.

It is an amenable number.

21711361 is a deficient number, since it is larger than the sum of its proper divisors (3544769).

21711361 is an equidigital number, since it uses as much as digits as its factorization.

21711361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443103 (or 443096 counting only the distinct ones).

The product of its digits is 252, while the sum is 22.

The square root of 21711361 is about 4659.5451494754. The cubic root of 21711361 is about 278.9731135476.

The spelling of 21711361 in words is "twenty-one million, seven hundred eleven thousand, three hundred sixty-one".