6557861 has 2 divisors, whose sum is σ = 6557862. Its totient is φ = 6557860.

The previous prime is 6557839. The next prime is 6557867. The reversal of 6557861 is 1687556.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6076225 + 481636 = 2465^2 + 694^2 .

It is a cyclic number.

It is not a de Polignac number, because 6557861 - 2⁶ = 6557797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6557867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3278930 + 3278931.

It is an arithmetic number, because the mean of its divisors is an integer number (3278931).

Almost surely, 2^6557861 is an apocalyptic number.

It is an amenable number.

6557861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6557861 is an equidigital number, since it uses as much as digits as its factorization.

6557861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 38.

The square root of 6557861 is about 2560.8320913328. The cubic root of 6557861 is about 187.1776838795.

The spelling of 6557861 in words is "six million, five hundred fifty-seven thousand, eight hundred sixty-one".