21676788 has 96 divisors (see below), whose sum is σ = 65560320. Its totient is φ = 6065280.

The previous prime is 21676771. The next prime is 21676793. The reversal of 21676788 is 88767612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39798 + ... + 40338.

It is an arithmetic number, because the mean of its divisors is an integer number (682920).

Almost surely, 2^21676788 is an apocalyptic number.

21676788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21676788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32780160).

21676788 is an abundant number, since it is smaller than the sum of its proper divisors (43883532).

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

21676788 is a wasteful number, since it uses less digits than its factorization.

21676788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 614 (or 606 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 21676788 is about 4655.8337599188. The cubic root of 21676788 is about 278.8249566833.

The spelling of 21676788 in words is "twenty-one million, six hundred seventy-six thousand, seven hundred eighty-eight".