21213612505522 has 16 divisors (see below), whose sum is σ = 31957471079352. Its totient is φ = 10561123525120.

The previous prime is 21213612505417. The next prime is 21213612505549. The reversal of 21213612505522 is 22550521631212.

It can be written as a sum of positive squares in 4 ways, for example, as 21162401268121 + 51211237401 = 4600261^2 + 226299^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34158078 + ... + 34773574.

Almost surely, 2^{21213612505522} is an apocalyptic number.

21213612505522 is a deficient number, since it is larger than the sum of its proper divisors (10743858573830).

21213612505522 is a wasteful number, since it uses less digits than its factorization.

21213612505522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689693.

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 21213612505522 in words is "twenty-one trillion, two hundred thirteen billion, six hundred twelve million, five hundred five thousand, five hundred twenty-two".