21521556060065 has 16 divisors (see below), whose sum is σ = 26553389296896. Its totient is φ = 16735329302400.

The previous prime is 21521556060029. The next prime is 21521556060091. The reversal of 21521556060065 is 56006065512512.

It is not a de Polignac number, because 21521556060065 - 2¹⁰ = 21521556059041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21521556059998 and 21521556060025.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193640387 + ... + 193751496.

It is an arithmetic number, because the mean of its divisors is an integer number (1659586831056).

Almost surely, 2^{21521556060065} is an apocalyptic number.

It is an amenable number.

21521556060065 is a deficient number, since it is larger than the sum of its proper divisors (5031833236831).

21521556060065 is a wasteful number, since it uses less digits than its factorization.

21521556060065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387392200.

The product of its (nonzero) digits is 540000, while the sum is 44.

The spelling of 21521556060065 in words is "twenty-one trillion, five hundred twenty-one billion, five hundred fifty-six million, sixty thousand, sixty-five".