1386256521 has 16 divisors (see below), whose sum is σ = 2059162560. Its totient is φ = 823663680.

The previous prime is 1386256513. The next prime is 1386256523. The reversal of 1386256521 is 1256526831.

It is not a de Polignac number, because 1386256521 - 2³ = 1386256513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 1386256521.

It is not an unprimeable number, because it can be changed into a prime (1386256523) 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 15 ways as a sum of consecutive naturals, for example, 611715 + ... + 613976.

It is an arithmetic number, because the mean of its divisors is an integer number (128697660).

Almost surely, 2^1386256521 is an apocalyptic number.

It is an amenable number.

1386256521 is a deficient number, since it is larger than the sum of its proper divisors (672906039).

1386256521 is a wasteful number, since it uses less digits than its factorization.

1386256521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1225736.

The product of its digits is 86400, while the sum is 39.

The square root of 1386256521 is about 37232.4659537882. The cubic root of 1386256521 is about 1115.0162601609.

The spelling of 1386256521 in words is "one billion, three hundred eighty-six million, two hundred fifty-six thousand, five hundred twenty-one".