21568460 has 48 divisors (see below), whose sum is σ = 48051360. Its totient is φ = 8117760.

The previous prime is 21568433. The next prime is 21568471. The reversal of 21568460 is 6486512.

21568460 = T₉₇ + T₉₈ + ... + T₅₀₆.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23327 + ... + 24233.

It is an arithmetic number, because the mean of its divisors is an integer number (1001070).

Almost surely, 2^21568460 is an apocalyptic number.

21568460 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 21568460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24025680).

21568460 is an abundant number, since it is smaller than the sum of its proper divisors (26482900).

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

21568460 is a wasteful number, since it uses less digits than its factorization.

21568460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986 (or 984 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 21568460 is about 4644.1856121391. The cubic root of 21568460 is about 278.3597124014.

The spelling of 21568460 in words is "twenty-one million, five hundred sixty-eight thousand, four hundred sixty".