21678977100 has 216 divisors, whose sum is σ = 70812887824. Its totient is φ = 5113152000.

The previous prime is 21678977081. The next prime is 21678977113. The reversal of 21678977100 is 177987612.

It is a self number, because there is not a number n which added to its sum of digits gives 21678977100.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1335030 + ... + 1351170.

Almost surely, 2^21678977100 is an apocalyptic number.

21678977100 is a gapful number since it is divisible by the number (20) 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 21678977100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35406443912).

21678977100 is an abundant number, since it is smaller than the sum of its proper divisors (49133910724).

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

21678977100 is a wasteful number, since it uses less digits than its factorization.

21678977100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16217 (or 16199 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 48.

The spelling of 21678977100 in words is "twenty-one billion, six hundred seventy-eight million, nine hundred seventy-seven thousand, one hundred".