10115661 has 4 divisors (see below), whose sum is σ = 13487552. Its totient is φ = 6743772.

The previous prime is 10115659. The next prime is 10115681. The reversal of 10115661 is 16651101.

10115661 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.

It is not a de Polignac number, because 10115661 - 2¹ = 10115659 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 (10115681) 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, 1685941 + ... + 1685946.

It is an arithmetic number, because the mean of its divisors is an integer number (3371888).

Almost surely, 2^10115661 is an apocalyptic number.

It is an amenable number.

10115661 is a deficient number, since it is larger than the sum of its proper divisors (3371891).

10115661 is an equidigital number, since it uses as much as digits as its factorization.

10115661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3371890.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 10115661 is about 3180.5126945195. The cubic root of 10115661 is about 216.2709006718.

Adding to 10115661 its reverse (16651101), we get a palindrome (26766762).

The spelling of 10115661 in words is "ten million, one hundred fifteen thousand, six hundred sixty-one".