1387205857 has 2 divisors, whose sum is σ = 1387205858. Its totient is φ = 1387205856.

The previous prime is 1387205851. The next prime is 1387205867. The reversal of 1387205857 is 7585027831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 781258401 + 605947456 = 27951^2 + 24616^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387205857 - 2¹¹ = 1387203809 is a prime.

It is not a weakly prime, because it can be changed into another prime (1387205851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 693602928 + 693602929.

It is an arithmetic number, because the mean of its divisors is an integer number (693602929).

Almost surely, 2^1387205857 is an apocalyptic number.

It is an amenable number.

1387205857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1387205857 is an equidigital number, since it uses as much as digits as its factorization.

1387205857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 470400, while the sum is 46.

The square root of 1387205857 is about 37245.2125379894. The cubic root of 1387205857 is about 1115.2707305082.

The spelling of 1387205857 in words is "one billion, three hundred eighty-seven million, two hundred five thousand, eight hundred fifty-seven".