15661241 has 8 divisors (see below), whose sum is σ = 15957000. Its totient is φ = 15368320.

The previous prime is 15661223. The next prime is 15661273. The reversal of 15661241 is 14216651.

It can be written as a sum of positive squares in 4 ways, for example, as 1000000 + 14661241 = 1000^2 + 3829^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15661241 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15661241.

It is not an unprimeable number, because it can be changed into a prime (15661291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12671 + ... + 13851.

It is an arithmetic number, because the mean of its divisors is an integer number (1994625).

Almost surely, 2^15661241 is an apocalyptic number.

It is an amenable number.

15661241 is a deficient number, since it is larger than the sum of its proper divisors (295759).

15661241 is a wasteful number, since it uses less digits than its factorization.

15661241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419.

The product of its digits is 1440, while the sum is 26.

The square root of 15661241 is about 3957.4285843209. The cubic root of 15661241 is about 250.1931360887.

Adding to 15661241 its reverse (14216651), we get a palindrome (29877892).

It can be divided in two parts, 1566 and 1241, that multiplied together give a triangular number (1943406 = T₁₉₇₁).

The spelling of 15661241 in words is "fifteen million, six hundred sixty-one thousand, two hundred forty-one".