1380438821 has 4 divisors (see below), whose sum is σ = 1382234700. Its totient is φ = 1378642944.

The previous prime is 1380438797. The next prime is 1380438823. The reversal of 1380438821 is 1288340831.

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 639837025 + 740601796 = 25295^2 + 27214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1380438821 - 2³⁰ = 306696997 is a prime.

It is a super-2 number, since 2×1380438821² = 3811222677047740082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1380438823) 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, 896786 + ... + 898323.

It is an arithmetic number, because the mean of its divisors is an integer number (345558675).

Almost surely, 2^1380438821 is an apocalyptic number.

It is an amenable number.

1380438821 is a deficient number, since it is larger than the sum of its proper divisors (1795879).

1380438821 is an equidigital number, since it uses as much as digits as its factorization.

1380438821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795878.

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 1380438821 is about 37154.2571046711. The cubic root of 1380438821 is about 1113.4542775511.

It can be divided in two parts, 13804 and 38821, that added together give a palindrome (52625).

The spelling of 1380438821 in words is "one billion, three hundred eighty million, four hundred thirty-eight thousand, eight hundred twenty-one".