1378221646 has 8 divisors (see below), whose sum is σ = 2106338904. Its totient is φ = 676108680.

The previous prime is 1378221643. The next prime is 1378221661. The reversal of 1378221646 is 6461228731.

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

It is a junction number, because it is equal to n+sod(n) for n = 1378221599 and 1378221608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378221641) 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 3 ways as a sum of consecutive naturals, for example, 6500940 + ... + 6501151.

It is an arithmetic number, because the mean of its divisors is an integer number (263292363).

Almost surely, 2^1378221646 is an apocalyptic number.

1378221646 is a deficient number, since it is larger than the sum of its proper divisors (728117258).

1378221646 is a wasteful number, since it uses less digits than its factorization.

1378221646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13002146.

The product of its digits is 96768, while the sum is 40.

The square root of 1378221646 is about 37124.4076855106. The cubic root of 1378221646 is about 1112.8578377732.

The spelling of 1378221646 in words is "one billion, three hundred seventy-eight million, two hundred twenty-one thousand, six hundred forty-six".