21677678 has 16 divisors (see below), whose sum is σ = 35552304. Its totient is φ = 9831360.

The previous prime is 21677653. The next prime is 21677681. The reversal of 21677678 is 87677612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12776 + ... + 14372.

It is an arithmetic number, because the mean of its divisors is an integer number (2222019).

Almost surely, 2^21677678 is an apocalyptic number.

21677678 is a deficient number, since it is larger than the sum of its proper divisors (13874626).

21677678 is a wasteful number, since it uses less digits than its factorization.

21677678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227.

The product of its digits is 197568, while the sum is 44.

The square root of 21677678 is about 4655.9293379518. The cubic root of 21677678 is about 278.8287726056.

The spelling of 21677678 in words is "twenty-one million, six hundred seventy-seven thousand, six hundred seventy-eight".