3847942521 has 6 divisors (see below), whose sum is σ = 5558139210. Its totient is φ = 2565295008.

The previous prime is 3847942477. The next prime is 3847942543. The reversal of 3847942521 is 1252497483.

3847942521 is a `hidden beast` number, since 3 + 84 + 7 + 9 + 42 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3843380025 + 4562496 = 61995^2 + 2136^2 .

It is not a de Polignac number, because 3847942521 - 2¹³ = 3847934329 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3847942321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 213774576 + ... + 213774593.

It is an arithmetic number, because the mean of its divisors is an integer number (926356535).

Almost surely, 2^3847942521 is an apocalyptic number.

It is an amenable number.

3847942521 is a deficient number, since it is larger than the sum of its proper divisors (1710196689).

3847942521 is a wasteful number, since it uses less digits than its factorization.

3847942521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427549175 (or 427549172 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 3847942521 is about 62031.7863760185. The cubic root of 3847942521 is about 1567.0259628980.

The spelling of 3847942521 in words is "three billion, eight hundred forty-seven million, nine hundred forty-two thousand, five hundred twenty-one".