21116678 has 24 divisors (see below), whose sum is σ = 35335440. Its totient is φ = 9455600.

The previous prime is 21116663. The next prime is 21116687. The reversal of 21116678 is 87661112.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16568 + ... + 17796.

It is an arithmetic number, because the mean of its divisors is an integer number (1472310).

Almost surely, 2^21116678 is an apocalyptic number.

21116678 is a deficient number, since it is larger than the sum of its proper divisors (14218762).

21116678 is a wasteful number, since it uses less digits than its factorization.

21116678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324 (or 1313 counting only the distinct ones).

The product of its digits is 4032, while the sum is 32.

The square root of 21116678 is about 4595.2886742837. The cubic root of 21116678 is about 276.4024357474.

The spelling of 21116678 in words is "twenty-one million, one hundred sixteen thousand, six hundred seventy-eight".