381765021 has 16 divisors (see below), whose sum is σ = 555763008. Its totient is φ = 231177600.

The previous prime is 381764993. The next prime is 381765053. The reversal of 381765021 is 120567183.

It is not a de Polignac number, because 381765021 - 2¹¹ = 381762973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381765091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41385 + ... + 49761.

It is an arithmetic number, because the mean of its divisors is an integer number (34735188).

Almost surely, 2^381765021 is an apocalyptic number.

It is an amenable number.

381765021 is a deficient number, since it is larger than the sum of its proper divisors (173997987).

381765021 is a wasteful number, since it uses less digits than its factorization.

381765021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9772.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 381765021 is about 19538.8080752128. The cubic root of 381765021 is about 725.4353444003.

The spelling of 381765021 in words is "three hundred eighty-one million, seven hundred sixty-five thousand, twenty-one".