381238821 has 12 divisors (see below), whose sum is σ = 583071372. Its totient is φ = 239208576.

The previous prime is 381238813. The next prime is 381238829. The reversal of 381238821 is 128832183.

It is an interprime number because it is at equal distance from previous prime (381238813) and next prime (381238829).

It can be written as a sum of positive squares in 2 ways, for example, as 338192100 + 43046721 = 18390^2 + 6561^2 .

It is not a de Polignac number, because 381238821 - 2³ = 381238813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381238829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1245726 + ... + 1246031.

It is an arithmetic number, because the mean of its divisors is an integer number (48589281).

Almost surely, 2^381238821 is an apocalyptic number.

It is an amenable number.

381238821 is a deficient number, since it is larger than the sum of its proper divisors (201832551).

381238821 is a wasteful number, since it uses less digits than its factorization.

381238821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2491780 (or 2491777 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 381238821 is about 19525.3379228120. The cubic root of 381238821 is about 725.1018935664.

The spelling of 381238821 in words is "three hundred eighty-one million, two hundred thirty-eight thousand, eight hundred twenty-one".