16651945 has 16 divisors (see below), whose sum is σ = 21183120. Its totient is φ = 12544000.

The previous prime is 16651937. The next prime is 16651949. The reversal of 16651945 is 54915661.

It can be written as a sum of positive squares in 8 ways, for example, as 1806336 + 14845609 = 1344^2 + 3853^2 .

It is not a de Polignac number, because 16651945 - 2³ = 16651937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16651949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4545 + ... + 7345.

It is an arithmetic number, because the mean of its divisors is an integer number (1323945).

Almost surely, 2^16651945 is an apocalyptic number.

It is an amenable number.

16651945 is a deficient number, since it is larger than the sum of its proper divisors (4531175).

16651945 is a wasteful number, since it uses less digits than its factorization.

16651945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876.

The product of its digits is 32400, while the sum is 37.

The square root of 16651945 is about 4080.6794777341. The cubic root of 16651945 is about 255.3612462961.

The spelling of 16651945 in words is "sixteen million, six hundred fifty-one thousand, nine hundred forty-five".