1380624821 has 2 divisors, whose sum is σ = 1380624822. Its totient is φ = 1380624820.

The previous prime is 1380624809. The next prime is 1380624823. The reversal of 1380624821 is 1284260831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1212014596 + 168610225 = 34814^2 + 12985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1380624821 is a prime.

It is a super-4 number, since 4×1380624821⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

Together with 1380624823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1380624823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690312410 + 690312411.

It is an arithmetic number, because the mean of its divisors is an integer number (690312411).

Almost surely, 2^1380624821 is an apocalyptic number.

It is an amenable number.

1380624821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1380624821 is an equidigital number, since it uses as much as digits as its factorization.

1380624821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 1380624821 is about 37156.7600982648. The cubic root of 1380624821 is about 1113.5042841605.

The spelling of 1380624821 in words is "one billion, three hundred eighty million, six hundred twenty-four thousand, eight hundred twenty-one".