13001661 has 16 divisors (see below), whose sum is σ = 19328320. Its totient is φ = 8637840.

The previous prime is 13001627. The next prime is 13001663. The reversal of 13001661 is 16610031.

13001661 is a `hidden beast` number, since 1 + 3 + 0 + 0 + 1 + 661 = 666.

13001661 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13001661 - 2⁷ = 13001533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13001663) 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, 9426 + ... + 10716.

It is an arithmetic number, because the mean of its divisors is an integer number (1208020).

Almost surely, 2^13001661 is an apocalyptic number.

It is an amenable number.

13001661 is a deficient number, since it is larger than the sum of its proper divisors (6326659).

13001661 is a wasteful number, since it uses less digits than its factorization.

13001661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1673 (or 1667 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 13001661 is about 3605.7816073634. The cubic root of 13001661 is about 235.1434826197.

Adding to 13001661 its reverse (16610031), we get a palindrome (29611692).

The spelling of 13001661 in words is "thirteen million, one thousand, six hundred sixty-one".