21611073 has 16 divisors (see below), whose sum is σ = 31525056. Its totient is φ = 13059840.

The previous prime is 21611041. The next prime is 21611087. The reversal of 21611073 is 37011612.

It is not a de Polignac number, because 21611073 - 2⁵ = 21611041 is a prime.

It is a super-3 number, since 3×21611073³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21615073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14365 + ... + 15797.

It is an arithmetic number, because the mean of its divisors is an integer number (1970316).

Almost surely, 2^21611073 is an apocalyptic number.

It is an amenable number.

21611073 is a deficient number, since it is larger than the sum of its proper divisors (9913983).

21611073 is a wasteful number, since it uses less digits than its factorization.

21611073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1904.

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

The square root of 21611073 is about 4648.7711279434. The cubic root of 21611073 is about 278.5429110659.

Adding to 21611073 its reverse (37011612), we get a palindrome (58622685).

The spelling of 21611073 in words is "twenty-one million, six hundred eleven thousand, seventy-three".