21306160 has 40 divisors (see below), whose sum is σ = 49795920. Its totient is φ = 8477952.

The previous prime is 21306149. The next prime is 21306167. The reversal of 21306160 is 6160312.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21306167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17739 + ... + 18901.

It is an arithmetic number, because the mean of its divisors is an integer number (1244898).

Almost surely, 2^21306160 is an apocalyptic number.

21306160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21306160 is an abundant number, since it is smaller than the sum of its proper divisors (28489760).

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

21306160 is a wasteful number, since it uses less digits than its factorization.

21306160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1405 (or 1399 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21306160 is about 4615.8596165828. The cubic root of 21306160 is about 277.2267038512.

Adding to 21306160 its reverse (6160312), we get a palindrome (27466472).

The spelling of 21306160 in words is "twenty-one million, three hundred six thousand, one hundred sixty".