2115661 has 4 divisors (see below), whose sum is σ = 2129824. Its totient is φ = 2101500.

The previous prime is 2115653. The next prime is 2115671. The reversal of 2115661 is 1665112.

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 a cyclic number.

It is not a de Polignac number, because 2115661 - 2³ = 2115653 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 (2115671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6855 + ... + 7156.

It is an arithmetic number, because the mean of its divisors is an integer number (532456).

2^2115661 is an apocalyptic number.

It is an amenable number.

2115661 is a deficient number, since it is larger than the sum of its proper divisors (14163).

2115661 is a wasteful number, since it uses less digits than its factorization.

2115661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14162.

The product of its digits is 360, while the sum is 22.

The square root of 2115661 is about 1454.5311959528. The cubic root of 2115661 is about 128.3754641381.

The spelling of 2115661 in words is "two million, one hundred fifteen thousand, six hundred sixty-one".