21639528548 has 48 divisors (see below), whose sum is σ = 45153013248. Its totient is φ = 8958912000.

The previous prime is 21639528527. The next prime is 21639528569. The reversal of 21639528548 is 84582593612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21639528527) and next prime (21639528569).

It is a self number, because there is not a number n which added to its sum of digits gives 21639528548.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 443423 + ... + 489798.

It is an arithmetic number, because the mean of its divisors is an integer number (940687776).

Almost surely, 2^21639528548 is an apocalyptic number.

It is an amenable number.

21639528548 is an abundant number, since it is smaller than the sum of its proper divisors (23513484700).

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

21639528548 is a wasteful number, since it uses less digits than its factorization.

21639528548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933284 (or 933282 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 53.

The spelling of 21639528548 in words is "twenty-one billion, six hundred thirty-nine million, five hundred twenty-eight thousand, five hundred forty-eight".