21011155548 has 24 divisors (see below), whose sum is σ = 51606347520. Its totient is φ = 6635101680.

The previous prime is 21011155483. The next prime is 21011155549. The reversal of 21011155548 is 84555111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011155549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46076868 + ... + 46077323.

It is an arithmetic number, because the mean of its divisors is an integer number (2150264480).

Almost surely, 2^21011155548 is an apocalyptic number.

It is an amenable number.

21011155548 is an abundant number, since it is smaller than the sum of its proper divisors (30595191972).

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

21011155548 is a wasteful number, since it uses less digits than its factorization.

21011155548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92154217 (or 92154215 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 33.

The spelling of 21011155548 in words is "twenty-one billion, eleven million, one hundred fifty-five thousand, five hundred forty-eight".