1387205856 has 72 divisors (see below), whose sum is σ = 4072146624. Its totient is φ = 447482880.

The previous prime is 1387205851. The next prime is 1387205857. The reversal of 1387205856 is 6585027831.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387205851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 68761 + ... + 86616.

It is an arithmetic number, because the mean of its divisors is an integer number (56557592).

Almost surely, 2^1387205856 is an apocalyptic number.

1387205856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1387205856 is an abundant number, since it is smaller than the sum of its proper divisors (2684940768).

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

1387205856 is a wasteful number, since it uses less digits than its factorization.

1387205856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155424 (or 155413 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The square root of 1387205856 is about 37245.2125245648. The cubic root of 1387205856 is about 1115.2707302403.

The spelling of 1387205856 in words is "one billion, three hundred eighty-seven million, two hundred five thousand, eight hundred fifty-six".