21542520216 has 64 divisors (see below), whose sum is σ = 61672665600. Its totient is φ = 6142745088.

The previous prime is 21542520193. The next prime is 21542520227. The reversal of 21542520216 is 61202524512.

It is a congruent number.

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, 42961 + ... + 211968.

It is an arithmetic number, because the mean of its divisors is an integer number (963635400).

Almost surely, 2^21542520216 is an apocalyptic number.

It is an amenable number.

21542520216 is an abundant number, since it is smaller than the sum of its proper divisors (40130145384).

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

21542520216 is a wasteful number, since it uses less digits than its factorization.

21542520216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255448 (or 255444 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 30.

It can be divided in two parts, 215425 and 20216, that added together give a triangular number (235641 = T₆₈₆).

The spelling of 21542520216 in words is "twenty-one billion, five hundred forty-two million, five hundred twenty thousand, two hundred sixteen".