16421550565 has 24 divisors (see below), whose sum is σ = 24129632160. Its totient is φ = 10667831328.

The previous prime is 16421550559. The next prime is 16421550577. The reversal of 16421550565 is 56505512461.

It is not a de Polignac number, because 16421550565 - 2⁹ = 16421550053 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1759207 + ... + 1768516.

It is an arithmetic number, because the mean of its divisors is an integer number (1005401340).

Almost surely, 2^16421550565 is an apocalyptic number.

It is an amenable number.

16421550565 is a deficient number, since it is larger than the sum of its proper divisors (7708081595).

16421550565 is a wasteful number, since it uses less digits than its factorization.

16421550565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3527761 (or 3527754 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 40.

The spelling of 16421550565 in words is "sixteen billion, four hundred twenty-one million, five hundred fifty thousand, five hundred sixty-five".