1378161220 has 24 divisors (see below), whose sum is σ = 2895821208. Its totient is φ = 550944000.

The previous prime is 1378161179. The next prime is 1378161247. The reversal of 1378161220 is 221618731.

It can be written as a sum of positive squares in 4 ways, for example, as 187635204 + 1190526016 = 13698^2 + 34504^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16890 + ... + 55150.

It is an arithmetic number, because the mean of its divisors is an integer number (120659217).

Almost surely, 2^1378161220 is an apocalyptic number.

1378161220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1378161220 is an abundant number, since it is smaller than the sum of its proper divisors (1517659988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1378161220 is a wasteful number, since it uses less digits than its factorization.

1378161220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40071 (or 40069 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 1378161220 is about 37123.5938454240. The cubic root of 1378161220 is about 1112.8415736910.

Adding to 1378161220 its reverse (221618731), we get a palindrome (1599779951).

The spelling of 1378161220 in words is "one billion, three hundred seventy-eight million, one hundred sixty-one thousand, two hundred twenty".