21676571 has 8 divisors (see below), whose sum is σ = 25279200. Its totient is φ = 18579624.

The previous prime is 21676553. The next prime is 21676579. The reversal of 21676571 is 17567612.

It is not a de Polignac number, because 21676571 - 2⁶ = 21676507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21676579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31256 + ... + 31941.

It is an arithmetic number, because the mean of its divisors is an integer number (3159900).

Almost surely, 2^21676571 is an apocalyptic number.

21676571 is a deficient number, since it is larger than the sum of its proper divisors (3602629).

21676571 is an frugal number, since it uses more digits than its factorization.

21676571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63218 (or 63204 counting only the distinct ones).

The product of its digits is 17640, while the sum is 35.

The square root of 21676571 is about 4655.8104557639. The cubic root of 21676571 is about 278.8240262684.

The spelling of 21676571 in words is "twenty-one million, six hundred seventy-six thousand, five hundred seventy-one".