6619861 has 2 divisors, whose sum is σ = 6619862. Its totient is φ = 6619860.

The previous prime is 6619849. The next prime is 6619867. The reversal of 6619861 is 1689166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4384836 + 2235025 = 2094^2 + 1495^2 .It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1986199 and 9916891.

It is a cyclic number.

It is not a de Polignac number, because 6619861 - 2⁵ = 6619829 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6619861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6619867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3309930 + 3309931.

It is an arithmetic number, because the mean of its divisors is an integer number (3309931).

Almost surely, 2^6619861 is an apocalyptic number.

It is an amenable number.

6619861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6619861 is an equidigital number, since it uses as much as digits as its factorization.

6619861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 37.

The square root of 6619861 is about 2572.9090539698. The cubic root of 6619861 is about 187.7657127528.

The spelling of 6619861 in words is "six million, six hundred nineteen thousand, eight hundred sixty-one".