10131661 has 4 divisors (see below), whose sum is σ = 10572192. Its totient is φ = 9691132.

The previous prime is 10131623. The next prime is 10131689. The reversal of 10131661 is 16613101.

10131661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16613101 = 313 ⋅53077.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10131661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10131601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220231 + ... + 220276.

It is an arithmetic number, because the mean of its divisors is an integer number (2643048).

Almost surely, 2^10131661 is an apocalyptic number.

It is an amenable number.

10131661 is a deficient number, since it is larger than the sum of its proper divisors (440531).

10131661 is an equidigital number, since it uses as much as digits as its factorization.

10131661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440530.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 10131661 is about 3183.0270184213. The cubic root of 10131661 is about 216.3848662545.

Adding to 10131661 its reverse (16613101), we get a palindrome (26744762).

The spelling of 10131661 in words is "ten million, one hundred thirty-one thousand, six hundred sixty-one".