21686676 has 48 divisors (see below), whose sum is σ = 58114560. Its totient is φ = 6225120.

The previous prime is 21686671. The next prime is 21686741. The reversal of 21686676 is 67668612.

It is a happy number.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21686671) 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, 1816 + ... + 6831.

It is an arithmetic number, because the mean of its divisors is an integer number (1210720).

Almost surely, 2^21686676 is an apocalyptic number.

It is an amenable number.

21686676 is an abundant number, since it is smaller than the sum of its proper divisors (36427884).

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

21686676 is a wasteful number, since it uses less digits than its factorization.

21686676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8684 (or 8682 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 21686676 is about 4656.8955324336. The cubic root of 21686676 is about 278.8673461441.

The spelling of 21686676 in words is "twenty-one million, six hundred eighty-six thousand, six hundred seventy-six".