6481661 has 4 divisors (see below), whose sum is σ = 6573024. Its totient is φ = 6390300.

The previous prime is 6481639. The next prime is 6481667. The reversal of 6481661 is 1661846.

It is a happy number.

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: 1661846 = 2 ⋅830923.

It is a cyclic number.

It is not a de Polignac number, because 6481661 - 2¹⁰ = 6480637 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 (6481667) 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, 45575 + ... + 45716.

It is an arithmetic number, because the mean of its divisors is an integer number (1643256).

Almost surely, 2^6481661 is an apocalyptic number.

It is an amenable number.

6481661 is a deficient number, since it is larger than the sum of its proper divisors (91363).

6481661 is an equidigital number, since it uses as much as digits as its factorization.

6481661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91362.

The product of its digits is 6912, while the sum is 32.

The square root of 6481661 is about 2545.9106425796. The cubic root of 6481661 is about 186.4498783581.

The spelling of 6481661 in words is "six million, four hundred eighty-one thousand, six hundred sixty-one".