21553064 has 16 divisors (see below), whose sum is σ = 43520820. Its totient is φ = 9947520.

The previous prime is 21553057. The next prime is 21553079. The reversal of 21553064 is 46035512.

It can be written as a sum of positive squares in 2 ways, for example, as 21548164 + 4900 = 4642^2 + 70^2 .

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103517 + ... + 103724.

Almost surely, 2^21553064 is an apocalyptic number.

It is an amenable number.

21553064 is an abundant number, since it is smaller than the sum of its proper divisors (21967756).

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

21553064 is a wasteful number, since it uses less digits than its factorization.

21553064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207260 (or 207256 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21553064 is about 4642.5277597447. The cubic root of 21553064 is about 278.2934637176.

Adding to 21553064 its reverse (46035512), we get a palindrome (67588576).

The spelling of 21553064 in words is "twenty-one million, five hundred fifty-three thousand, sixty-four".