6620861 has 4 divisors (see below), whose sum is σ = 7130172. Its totient is φ = 6111552.

The previous prime is 6620857. The next prime is 6620863. The reversal of 6620861 is 1680266.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1976836 + 4644025 = 1406^2 + 2155^2 .

It is a cyclic number.

It is not a de Polignac number, because 6620861 - 2² = 6620857 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 (6620863) 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, 254636 + ... + 254661.

It is an arithmetic number, because the mean of its divisors is an integer number (1782543).

Almost surely, 2^6620861 is an apocalyptic number.

It is an amenable number.

6620861 is a deficient number, since it is larger than the sum of its proper divisors (509311).

6620861 is a wasteful number, since it uses less digits than its factorization.

6620861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509310.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 6620861 is about 2573.1033791902. The cubic root of 6620861 is about 187.7751669422.

The spelling of 6620861 in words is "six million, six hundred twenty thousand, eight hundred sixty-one".