1381541821 has 6 divisors (see below), whose sum is σ = 1518554366. Its totient is φ = 1255947000.

The previous prime is 1381541807. The next prime is 1381541827. The reversal of 1381541821 is 1281451831.

It can be written as a sum of positive squares in only one way, i.e., 949317721 + 432224100 = 30811^2 + 20790^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1381541821 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 (1381541827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5708730 + ... + 5708971.

Almost surely, 2^1381541821 is an apocalyptic number.

1381541821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1381541821 is a deficient number, since it is larger than the sum of its proper divisors (137012545).

1381541821 is a wasteful number, since it uses less digits than its factorization.

1381541821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11417723 (or 11417712 counting only the distinct ones).

The product of its digits is 7680, while the sum is 34.

The square root of 1381541821 is about 37169.0976619019. The cubic root of 1381541821 is about 1113.7507564899.

The spelling of 1381541821 in words is "one billion, three hundred eighty-one million, five hundred forty-one thousand, eight hundred twenty-one".