21560860 has 12 divisors (see below), whose sum is σ = 45277848. Its totient is φ = 8624336.

The previous prime is 21560843. The next prime is 21560863. The reversal of 21560860 is 6806512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21560863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 539002 + ... + 539041.

It is an arithmetic number, because the mean of its divisors is an integer number (3773154).

Almost surely, 2^21560860 is an apocalyptic number.

21560860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21560860 is an abundant number, since it is smaller than the sum of its proper divisors (23716988).

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

21560860 is a wasteful number, since it uses less digits than its factorization.

21560860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078052 (or 1078050 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 21560860 is about 4643.3673126299. The cubic root of 21560860 is about 278.3270136931.

It can be divided in two parts, 215 and 60860, that added together give a triangular number (61075 = T₃₄₉).

The spelling of 21560860 in words is "twenty-one million, five hundred sixty thousand, eight hundred sixty".