6561955 has 4 divisors (see below), whose sum is σ = 7874352. Its totient is φ = 5249560.

The previous prime is 6561943. The next prime is 6561991. The reversal of 6561955 is 5591656.

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

It is not a de Polignac number, because 6561955 - 2⁷ = 6561827 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 656191 + ... + 656200.

It is an arithmetic number, because the mean of its divisors is an integer number (1968588).

Almost surely, 2^6561955 is an apocalyptic number.

6561955 is a deficient number, since it is larger than the sum of its proper divisors (1312397).

6561955 is a wasteful number, since it uses less digits than its factorization.

6561955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312396.

The product of its digits is 40500, while the sum is 37.

The square root of 6561955 is about 2561.6313161733. The cubic root of 6561955 is about 187.2166267618.

Subtracting from 6561955 its reverse (5591656), we obtain a cube (970299 = 99³).

The spelling of 6561955 in words is "six million, five hundred sixty-one thousand, nine hundred fifty-five".