16005645640 has 16 divisors (see below), whose sum is σ = 36012702780. Its totient is φ = 6402258240.

The previous prime is 16005645599. The next prime is 16005645647. The reversal of 16005645640 is 4654650061.

It can be written as a sum of positive squares in 2 ways, for example, as 15995672676 + 9972964 = 126474^2 + 3158^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 16005645640.

It is not an unprimeable number, because it can be changed into a prime (16005645647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200070531 + ... + 200070610.

Almost surely, 2^16005645640 is an apocalyptic number.

16005645640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16005645640 is an abundant number, since it is smaller than the sum of its proper divisors (20007057140).

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

16005645640 is a wasteful number, since it uses less digits than its factorization.

16005645640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400141152 (or 400141148 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 16005645640 in words is "sixteen billion, five million, six hundred forty-five thousand, six hundred forty".