1378992561 has 8 divisors (see below), whose sum is σ = 1897968384. Its totient is φ = 889672560.

The previous prime is 1378992533. The next prime is 1378992569. The reversal of 1378992561 is 1652998731.

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

It is not a de Polignac number, because 1378992561 - 2⁶ = 1378992497 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1378992569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7413846 + ... + 7414031.

It is an arithmetic number, because the mean of its divisors is an integer number (237246048).

Almost surely, 2^1378992561 is an apocalyptic number.

It is an amenable number.

1378992561 is a deficient number, since it is larger than the sum of its proper divisors (518975823).

1378992561 is a wasteful number, since it uses less digits than its factorization.

1378992561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14827911.

The product of its digits is 816480, while the sum is 51.

The square root of 1378992561 is about 37134.7890932479. The cubic root of 1378992561 is about 1113.0652932508.

The spelling of 1378992561 in words is "one billion, three hundred seventy-eight million, nine hundred ninety-two thousand, five hundred sixty-one".