21318064 has 10 divisors (see below), whose sum is σ = 41303780. Its totient is φ = 10659024.

The previous prime is 21318047. The next prime is 21318091. The reversal of 21318064 is 46081312.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 666174 + ... + 666205.

It is an arithmetic number, because the mean of its divisors is an integer number (4130378).

Almost surely, 2^21318064 is an apocalyptic number.

It is an amenable number.

21318064 is a deficient number, since it is larger than the sum of its proper divisors (19985716).

21318064 is a wasteful number, since it uses less digits than its factorization.

21318064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1332387 (or 1332381 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 21318064 is about 4617.1489038150. The cubic root of 21318064 is about 277.2783241694.

Adding to 21318064 its reverse (46081312), we get a palindrome (67399376).

The spelling of 21318064 in words is "twenty-one million, three hundred eighteen thousand, sixty-four".