21276580 has 96 divisors (see below), whose sum is σ = 52214400. Its totient is φ = 7216128.

The previous prime is 21276569. The next prime is 21276583. The reversal of 21276580 is 8567212.

21276580 = T₁₀₂₅ + T₁₀₂₆ + ... + T₁₀₆₃.

It is not an unprimeable number, because it can be changed into a prime (21276583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 291424 + ... + 291496.

It is an arithmetic number, because the mean of its divisors is an integer number (543900).

Almost surely, 2^21276580 is an apocalyptic number.

21276580 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 21276580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26107200).

21276580 is an abundant number, since it is smaller than the sum of its proper divisors (30937820).

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

21276580 is a wasteful number, since it uses less digits than its factorization.

21276580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 21276580 is about 4612.6543334614. The cubic root of 21276580 is about 277.0983503020.

The spelling of 21276580 in words is "twenty-one million, two hundred seventy-six thousand, five hundred eighty".