21542820752 has 20 divisors (see below), whose sum is σ = 43178499420. Its totient is φ = 10399982208.

The previous prime is 21542820727. The next prime is 21542820757. The reversal of 21542820752 is 25702824512.

It can be written as a sum of positive squares in 2 ways, for example, as 11963109376 + 9579711376 = 109376^2 + 97876^2 .

It is not an unprimeable number, because it can be changed into a prime (21542820757) by changing a digit.

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, 23213783 + ... + 23214710.

It is an arithmetic number, because the mean of its divisors is an integer number (2158924971).

Almost surely, 2^21542820752 is an apocalyptic number.

It is an amenable number.

21542820752 is an abundant number, since it is smaller than the sum of its proper divisors (21635678668).

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

21542820752 is a wasteful number, since it uses less digits than its factorization.

21542820752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46428530 (or 46428524 counting only the distinct ones).

The product of its (nonzero) digits is 89600, while the sum is 38.

The spelling of 21542820752 in words is "twenty-one billion, five hundred forty-two million, eight hundred twenty thousand, seven hundred fifty-two".