21611703 has 4 divisors (see below), whose sum is σ = 28815608. Its totient is φ = 14407800.

The previous prime is 21611693. The next prime is 21611731. The reversal of 21611703 is 30711612.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21611703 - 2⁴ = 21611687 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21611703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611783) 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 3 ways as a sum of consecutive naturals, for example, 3601948 + ... + 3601953.

It is an arithmetic number, because the mean of its divisors is an integer number (7203902).

Almost surely, 2^21611703 is an apocalyptic number.

21611703 is a deficient number, since it is larger than the sum of its proper divisors (7203905).

21611703 is an equidigital number, since it uses as much as digits as its factorization.

21611703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7203904.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 21611703 is about 4648.8388872922. The cubic root of 21611703 is about 278.5456177081.

Subtracting 21611703 from its reverse (30711612), we obtain a palindrome (9099909).

The spelling of 21611703 in words is "twenty-one million, six hundred eleven thousand, seven hundred three".