21676081 has 12 divisors (see below), whose sum is σ = 25321908. Its totient is φ = 18500832.

The previous prime is 21676033. The next prime is 21676091. The reversal of 21676081 is 18067612.

It can be written as a sum of positive squares in 2 ways, for example, as 4036081 + 17640000 = 2009^2 + 4200^2 .

It is not a de Polignac number, because 21676081 - 2¹¹ = 21674033 is a prime.

It is a super-2 number, since 2×21676081² = 939704975037122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21676091) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12775 + ... + 14371.

It is an arithmetic number, because the mean of its divisors is an integer number (2110159).

Almost surely, 2^21676081 is an apocalyptic number.

It is an amenable number.

21676081 is a deficient number, since it is larger than the sum of its proper divisors (3645827).

21676081 is a wasteful number, since it uses less digits than its factorization.

21676081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888 (or 1881 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21676081 is about 4655.7578330493. The cubic root of 21676081 is about 278.8219253088.

The spelling of 21676081 in words is "twenty-one million, six hundred seventy-six thousand, eighty-one".