21227648 has 32 divisors (see below), whose sum is σ = 45546060. Its totient is φ = 9796608.

The previous prime is 21227629. The next prime is 21227671. The reversal of 21227648 is 84672212.

It can be written as a sum of positive squares in 2 ways, for example, as 20720704 + 506944 = 4552^2 + 712^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×21227648² = 901226079223808, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4715 + ... + 8042.

Almost surely, 2^21227648 is an apocalyptic number.

It is an amenable number.

21227648 is an abundant number, since it is smaller than the sum of its proper divisors (24318412).

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

21227648 is a wasteful number, since it uses less digits than its factorization.

21227648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12784 (or 12772 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 21227648 is about 4607.3471759788. The cubic root of 21227648 is about 276.8857631269.

The spelling of 21227648 in words is "twenty-one million, two hundred twenty-seven thousand, six hundred forty-eight".