21082680 has 128 divisors (see below), whose sum is σ = 71438400. Its totient is φ = 5598720.

The previous prime is 21082673. The next prime is 21082687. The reversal of 21082680 is 8628012.

It is an interprime number because it is at equal distance from previous prime (21082673) and next prime (21082687).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21082687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87360 + ... + 87600.

Almost surely, 2^21082680 is an apocalyptic number.

21082680 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 21082680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35719200).

21082680 is an abundant number, since it is smaller than the sum of its proper divisors (50355720).

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

21082680 is an equidigital number, since it uses as much as digits as its factorization.

21082680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21082680 is about 4591.5879606080. The cubic root of 21082680 is about 276.2540194470.

The spelling of 21082680 in words is "twenty-one million, eighty-two thousand, six hundred eighty".