6187664421 has 6 divisors (see below), whose sum is σ = 8937737510. Its totient is φ = 4125109608.

The previous prime is 6187664411. The next prime is 6187664429. The reversal of 6187664421 is 1244667816.

6187664421 is a `hidden beast` number, since 618 + 7 + 6 + 6 + 4 + 4 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6184092321 + 3572100 = 78639^2 + 1890^2 .

It is not a de Polignac number, because 6187664421 - 2⁷ = 6187664293 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 (6187664429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 343759126 + ... + 343759143.

Almost surely, 2^6187664421 is an apocalyptic number.

It is an amenable number.

6187664421 is a deficient number, since it is larger than the sum of its proper divisors (2750073089).

6187664421 is a wasteful number, since it uses less digits than its factorization.

6187664421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687518275 (or 687518272 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 6187664421 is about 78661.7087343010. The cubic root of 6187664421 is about 1835.8713768167.

The spelling of 6187664421 in words is "six billion, one hundred eighty-seven million, six hundred sixty-four thousand, four hundred twenty-one".