21122523648 has 90 divisors (see below), whose sum is σ = 60989519877. Its totient is φ = 7037552640.

The previous prime is 21122523581. The next prime is 21122523673. The reversal of 21122523648 is 84632522112.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

21122523648 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 2 + 5 + 2 + 3 + 648 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 14993512704 + 6129010944 = 122448^2 + 78288^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=102768.

It is a super-2 number, since 2×21122523648² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9864658 + ... + 9866798.

Almost surely, 2^21122523648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21122523648

21122523648 is an abundant number, since it is smaller than the sum of its proper divisors (39866996229).

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

21122523648 is an frugal number, since it uses more digits than its factorization.

21122523648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4306 (or 2146 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The spelling of 21122523648 in words is "twenty-one billion, one hundred twenty-two million, five hundred twenty-three thousand, six hundred forty-eight".