21051516606 has 16 divisors (see below), whose sum is σ = 42200725248. Its totient is φ = 7000890200.

The previous prime is 21051516599. The next prime is 21051516641. The reversal of 21051516606 is 60661515012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4067700 + ... + 4072871.

It is an arithmetic number, because the mean of its divisors is an integer number (2637545328).

Almost surely, 2^21051516606 is an apocalyptic number.

21051516606 is an abundant number, since it is smaller than the sum of its proper divisors (21149208642).

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

21051516606 is a wasteful number, since it uses less digits than its factorization.

21051516606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8141007.

The product of its (nonzero) digits is 10800, while the sum is 33.

The spelling of 21051516606 in words is "twenty-one billion, fifty-one million, five hundred sixteen thousand, six hundred six".