21711315 has 16 divisors (see below), whose sum is σ = 35859456. Its totient is φ = 11205600.

The previous prime is 21711307. The next prime is 21711317. The reversal of 21711315 is 51311712.

It is a happy number.

It is not a de Polignac number, because 21711315 - 2³ = 21711307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21711291 and 21711300.

It is not an unprimeable number, because it can be changed into a prime (21711317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22881 + ... + 23810.

It is an arithmetic number, because the mean of its divisors is an integer number (2241216).

Almost surely, 2^21711315 is an apocalyptic number.

21711315 is a deficient number, since it is larger than the sum of its proper divisors (14148141).

21711315 is a wasteful number, since it uses less digits than its factorization.

21711315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46730.

The product of its digits is 210, while the sum is 21.

The square root of 21711315 is about 4659.5402133687. The cubic root of 21711315 is about 278.9729165267.

It can be divided in two parts, 2171 and 1315, that added together give a triangular number (3486 = T₈₃).

The spelling of 21711315 in words is "twenty-one million, seven hundred eleven thousand, three hundred fifteen".