21172676 has 12 divisors (see below), whose sum is σ = 42345408. Its totient is φ = 9073992.

The previous prime is 21172663. The next prime is 21172691. The reversal of 21172676 is 67627112.

21172676 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 378056 + ... + 378111.

It is an arithmetic number, because the mean of its divisors is an integer number (3528784).

Almost surely, 2^21172676 is an apocalyptic number.

It is an amenable number.

21172676 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21172676 is a wasteful number, since it uses less digits than its factorization.

21172676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756178 (or 756176 counting only the distinct ones).

The product of its digits is 7056, while the sum is 32.

The square root of 21172676 is about 4601.3776198004. The cubic root of 21172676 is about 276.6465448826.

Adding to 21172676 its reverse (67627112), we get a palindrome (88799788).

The spelling of 21172676 in words is "twenty-one million, one hundred seventy-two thousand, six hundred seventy-six".