16505651655 has 24 divisors (see below), whose sum is σ = 28657605600. Its totient is φ = 8788303680.

The previous prime is 16505651651. The next prime is 16505651681. The reversal of 16505651655 is 55615650561.

It is not a de Polignac number, because 16505651655 - 2² = 16505651651 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 16505651655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16505651651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 279216 + ... + 333125.

It is an arithmetic number, because the mean of its divisors is an integer number (1194066900).

Almost surely, 2^16505651655 is an apocalyptic number.

16505651655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

16505651655 is a deficient number, since it is larger than the sum of its proper divisors (12151953945).

16505651655 is a wasteful number, since it uses less digits than its factorization.

16505651655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612951 (or 612948 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 45.

The spelling of 16505651655 in words is "sixteen billion, five hundred five million, six hundred fifty-one thousand, six hundred fifty-five".