1378161221 has 8 divisors (see below), whose sum is σ = 1391157504. Its totient is φ = 1365179200.

The previous prime is 1378161179. The next prime is 1378161247. The reversal of 1378161221 is 1221618731.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1378161221 - 2³⁰ = 304419397 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 (1378161271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355946 + ... + 359796.

It is an arithmetic number, because the mean of its divisors is an integer number (173894688).

Almost surely, 2^1378161221 is an apocalyptic number.

It is an amenable number.

1378161221 is a deficient number, since it is larger than the sum of its proper divisors (12996283).

1378161221 is a wasteful number, since it uses less digits than its factorization.

1378161221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7131.

The product of its digits is 4032, while the sum is 32.

The square root of 1378161221 is about 37123.5938588925. The cubic root of 1378161221 is about 1112.8415739601.

Adding to 1378161221 its reverse (1221618731), we get a palindrome (2599779952).

The spelling of 1378161221 in words is "one billion, three hundred seventy-eight million, one hundred sixty-one thousand, two hundred twenty-one".