6136878221 has 4 divisors (see below), whose sum is σ = 6237482844. Its totient is φ = 6036273600.

The previous prime is 6136878173. The next prime is 6136878227. The reversal of 6136878221 is 1228786316.

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 434514025 + 5702364196 = 20845^2 + 75514^2 .

It is a cyclic number.

It is not a de Polignac number, because 6136878221 - 2²⁶ = 6069769357 is a prime.

It is a super-2 number, since 2×6136878221² = 75322548598768249682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6136878227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50302220 + ... + 50302341.

It is an arithmetic number, because the mean of its divisors is an integer number (1559370711).

Almost surely, 2^6136878221 is an apocalyptic number.

6136878221 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

6136878221 is a deficient number, since it is larger than the sum of its proper divisors (100604623).

6136878221 is a wasteful number, since it uses less digits than its factorization.

6136878221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100604622.

The product of its digits is 193536, while the sum is 44.

The square root of 6136878221 is about 78338.2296264091. The cubic root of 6136878221 is about 1830.8348407052.

The spelling of 6136878221 in words is "six billion, one hundred thirty-six million, eight hundred seventy-eight thousand, two hundred twenty-one".