21601064 has 16 divisors (see below), whose sum is σ = 40799700. Its totient is φ = 10721152.

The previous prime is 21601061. The next prime is 21601121. The reversal of 21601064 is 46010612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21548164 + 52900 = 4642^2 + 230^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21601061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8759 + ... + 10950.

Almost surely, 2^21601064 is an apocalyptic number.

It is an amenable number.

21601064 is a deficient number, since it is larger than the sum of its proper divisors (19198636).

21601064 is a wasteful number, since it uses less digits than its factorization.

21601064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19852 (or 19848 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21601064 is about 4647.6944822137. The cubic root of 21601064 is about 278.4999027662.

Adding to 21601064 its reverse (46010612), we get a palindrome (67611676).

The spelling of 21601064 in words is "twenty-one million, six hundred one thousand, sixty-four".