16001645 has 12 divisors (see below), whose sum is σ = 21107100. Its totient is φ = 11637120.

The previous prime is 16001599. The next prime is 16001659. The reversal of 16001645 is 54610061.

It can be written as a sum of positive squares in 2 ways, for example, as 3455881 + 12545764 = 1859^2 + 3542^2 .

It is not a de Polignac number, because 16001645 - 2¹² = 15997549 is a prime.

It is a super-3 number, since 3×16001645³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16001645.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12620 + ... + 13829.

It is an arithmetic number, because the mean of its divisors is an integer number (1758925).

Almost surely, 2^16001645 is an apocalyptic number.

It is an amenable number.

16001645 is a deficient number, since it is larger than the sum of its proper divisors (5105455).

16001645 is a wasteful number, since it uses less digits than its factorization.

16001645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26476 (or 26465 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 16001645 is about 4000.2056197151. The cubic root of 16001645 is about 251.9928453919.

It can be divided in two parts, 160016 and 45, that added together give a palindrome (160061).

The spelling of 16001645 in words is "sixteen million, one thousand, six hundred forty-five".