6561938169 has 16 divisors (see below), whose sum is σ = 9886161600. Its totient is φ = 4300478208.

The previous prime is 6561938167. The next prime is 6561938179. The reversal of 6561938169 is 9618391656.

6561938169 is a `hidden beast` number, since 6 + 5 + 619 + 3 + 8 + 16 + 9 = 666.

It is not a de Polignac number, because 6561938169 - 2¹ = 6561938167 is a prime.

It is a super-2 number, since 2×6561938169² = 86118065067558145122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6561938167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2058024 + ... + 2061209.

It is an arithmetic number, because the mean of its divisors is an integer number (617885100).

Almost surely, 2^6561938169 is an apocalyptic number.

It is an amenable number.

6561938169 is a deficient number, since it is larger than the sum of its proper divisors (3324223431).

6561938169 is a wasteful number, since it uses less digits than its factorization.

6561938169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4119301 (or 4119295 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 54.

The square root of 6561938169 is about 81005.7909596592. The cubic root of 6561938169 is about 1872.1646669540.

The spelling of 6561938169 in words is "six billion, five hundred sixty-one million, nine hundred thirty-eight thousand, one hundred sixty-nine".