13406661 has 16 divisors (see below), whose sum is σ = 20070400. Its totient is φ = 8843904.

The previous prime is 13406651. The next prime is 13406711. The reversal of 13406661 is 16660431.

It is not a de Polignac number, because 13406661 - 2¹¹ = 13404613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13406651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60 + ... + 5178.

It is an arithmetic number, because the mean of its divisors is an integer number (1254400).

Almost surely, 2^13406661 is an apocalyptic number.

It is an amenable number.

13406661 is a deficient number, since it is larger than the sum of its proper divisors (6663739).

13406661 is an equidigital number, since it uses as much as digits as its factorization.

13406661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5225 (or 5219 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 13406661 is about 3661.5107537736. The cubic root of 13406661 is about 237.5601236518.

It can be divided in two parts, 1340 and 6661, that added together give a triangular number (8001 = T₁₂₆).

The spelling of 13406661 in words is "thirteen million, four hundred six thousand, six hundred sixty-one".