21146560 has 28 divisors (see below), whose sum is σ = 50356008. Its totient is φ = 8458496.

The previous prime is 21146551. The next prime is 21146561. The reversal of 21146560 is 6564112.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21146561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32722 + ... + 33361.

Almost surely, 2^21146560 is an apocalyptic number.

21146560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21146560 is an abundant number, since it is smaller than the sum of its proper divisors (29209448).

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

21146560 is an equidigital number, since it uses as much as digits as its factorization.

21146560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66100 (or 66090 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21146560 is about 4598.5388983894. The cubic root of 21146560 is about 276.5327524049.

The spelling of 21146560 in words is "twenty-one million, one hundred forty-six thousand, five hundred sixty".