380166821 has 4 divisors (see below), whose sum is σ = 383654700. Its totient is φ = 376678944.

The previous prime is 380166799. The next prime is 380166851. The reversal of 380166821 is 128661083.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 111534721 + 268632100 = 10561^2 + 16390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-380166821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (380166851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1743776 + ... + 1743993.

It is an arithmetic number, because the mean of its divisors is an integer number (95913675).

Almost surely, 2^380166821 is an apocalyptic number.

It is an amenable number.

380166821 is a deficient number, since it is larger than the sum of its proper divisors (3487879).

380166821 is a wasteful number, since it uses less digits than its factorization.

380166821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3487878.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 380166821 is about 19497.8670884792. The cubic root of 380166821 is about 724.4216209957.

The spelling of 380166821 in words is "three hundred eighty million, one hundred sixty-six thousand, eight hundred twenty-one".