387830021 has 8 divisors (see below), whose sum is σ = 401653080. Its totient is φ = 374036992.

The previous prime is 387830017. The next prime is 387830059. The reversal of 387830021 is 120038783.

It can be written as a sum of positive squares in 4 ways, for example, as 8008900 + 379821121 = 2830^2 + 19489^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 387830021 - 2² = 387830017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 387830021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (387830011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20621 + ... + 34653.

It is an arithmetic number, because the mean of its divisors is an integer number (50206635).

Almost surely, 2^387830021 is an apocalyptic number.

It is an amenable number.

387830021 is a deficient number, since it is larger than the sum of its proper divisors (13823059).

387830021 is a wasteful number, since it uses less digits than its factorization.

387830021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15015.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 387830021 is about 19693.4004427879. The cubic root of 387830021 is about 729.2567784463.

The spelling of 387830021 in words is "three hundred eighty-seven million, eight hundred thirty thousand, twenty-one".