3852721638 has 32 divisors (see below), whose sum is σ = 8598376800. Its totient is φ = 1278724608.

The previous prime is 3852721603. The next prime is 3852721643. The reversal of 3852721638 is 8361272583.

3852721638 is a `hidden beast` number, since 3 + 8 + 5 + 2 + 7 + 2 + 1 + 638 = 666.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 3852721593 and 3852721602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140523 + ... + 165686.

It is an arithmetic number, because the mean of its divisors is an integer number (268699275).

Almost surely, 2^3852721638 is an apocalyptic number.

3852721638 is an abundant number, since it is smaller than the sum of its proper divisors (4745655162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3852721638 is a wasteful number, since it uses less digits than its factorization.

3852721638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306453 (or 306447 counting only the distinct ones).

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

The square root of 3852721638 is about 62070.2959393622. The cubic root of 3852721638 is about 1567.6744395048.

The spelling of 3852721638 in words is "three billion, eight hundred fifty-two million, seven hundred twenty-one thousand, six hundred thirty-eight".