6155878221 has 24 divisors (see below), whose sum is σ = 9052992000. Its totient is φ = 4029695232.

The previous prime is 6155878207. The next prime is 6155878243. The reversal of 6155878221 is 1228785516.

6155878221 is a `hidden beast` number, since 6 + 1 + 558 + 78 + 2 + 21 = 666.

It is not a de Polignac number, because 6155878221 - 2¹⁷ = 6155747149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6155878271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 487060 + ... + 499538.

It is an arithmetic number, because the mean of its divisors is an integer number (377208000).

Almost surely, 2^6155878221 is an apocalyptic number.

It is an amenable number.

6155878221 is a deficient number, since it is larger than the sum of its proper divisors (2897113779).

6155878221 is a wasteful number, since it uses less digits than its factorization.

6155878221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13473 (or 13470 counting only the distinct ones).

The product of its digits is 268800, while the sum is 45.

The square root of 6155878221 is about 78459.4049238203. The cubic root of 6155878221 is about 1832.7223380564.

The spelling of 6155878221 in words is "six billion, one hundred fifty-five million, eight hundred seventy-eight thousand, two hundred twenty-one".