21127680 has 240 divisors, whose sum is σ = 84262464. Its totient is φ = 4792320.

The previous prime is 21127679. The next prime is 21127699. The reversal of 21127680 is 8672112.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161215 + ... + 161345.

Almost surely, 2^21127680 is an apocalyptic number.

21127680 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 21127680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42131232).

21127680 is an abundant number, since it is smaller than the sum of its proper divisors (63134784).

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

21127680 is a wasteful number, since it uses less digits than its factorization.

21127680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 21127680 is about 4596.4856140317. The cubic root of 21127680 is about 276.4504302224.

Adding to 21127680 its reverse (8672112), we get a palindrome (29799792).

The spelling of 21127680 in words is "twenty-one million, one hundred twenty-seven thousand, six hundred eighty".