1387720945 has 16 divisors (see below), whose sum is σ = 1794194640. Its totient is φ = 1024303104.

The previous prime is 1387720933. The next prime is 1387720967. The reversal of 1387720945 is 5490277831.

It can be written as a sum of positive squares in 8 ways, for example, as 9529569 + 1378191376 = 3087^2 + 37124^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387720945 - 2⁵ = 1387720913 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1387720895 and 1387720904.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 202617 + ... + 209353.

It is an arithmetic number, because the mean of its divisors is an integer number (112137165).

Almost surely, 2^1387720945 is an apocalyptic number.

It is an amenable number.

1387720945 is a deficient number, since it is larger than the sum of its proper divisors (406473695).

1387720945 is a wasteful number, since it uses less digits than its factorization.

1387720945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9924.

The product of its (nonzero) digits is 423360, while the sum is 46.

The square root of 1387720945 is about 37252.1267178130. The cubic root of 1387720945 is about 1115.4087517159.

The spelling of 1387720945 in words is "one billion, three hundred eighty-seven million, seven hundred twenty thousand, nine hundred forty-five".