21082860 has 36 divisors (see below), whose sum is σ = 63951888. Its totient is φ = 5622048.

The previous prime is 21082849. The next prime is 21082861. The reversal of 21082860 is 6828012.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21082861) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58384 + ... + 58743.

Almost surely, 2^21082860 is an apocalyptic number.

21082860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21082860 is an abundant number, since it is smaller than the sum of its proper divisors (42869028).

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

21082860 is a wasteful number, since it uses less digits than its factorization.

21082860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117142 (or 117137 counting only the distinct ones).

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

The square root of 21082860 is about 4591.6075616281. The cubic root of 21082860 is about 276.2548056466.

The spelling of 21082860 in words is "twenty-one million, eighty-two thousand, eight hundred sixty".