6471661 has 4 divisors (see below), whose sum is σ = 7396192. Its totient is φ = 5547132.

The previous prime is 6471649. The next prime is 6471667. The reversal of 6471661 is 1661746.

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: 1661746 = 2 ⋅830873.

It is a cyclic number.

It is not a de Polignac number, because 6471661 - 2¹⁵ = 6438893 is a prime.

It is a super-3 number, since 3×6471661³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6471667) 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, 462255 + ... + 462268.

It is an arithmetic number, because the mean of its divisors is an integer number (1849048).

Almost surely, 2^6471661 is an apocalyptic number.

It is an amenable number.

6471661 is a deficient number, since it is larger than the sum of its proper divisors (924531).

6471661 is an equidigital number, since it uses as much as digits as its factorization.

6471661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924530.

The product of its digits is 6048, while the sum is 31.

The square root of 6471661 is about 2543.9459506837. The cubic root of 6471661 is about 186.3539431513.

The spelling of 6471661 in words is "six million, four hundred seventy-one thousand, six hundred sixty-one".