1387205849 has 4 divisors (see below), whose sum is σ = 1421040180. Its totient is φ = 1353371520.

The previous prime is 1387205839. The next prime is 1387205851. The reversal of 1387205849 is 9485027831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9485027831 = 23333 ⋅406507.

It can be written as a sum of positive squares in 2 ways, for example, as 374693449 + 1012512400 = 19357^2 + 31820^2 .

It is a cyclic number.

It is not a de Polignac number, because 1387205849 - 2²⁰ = 1386157273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1387205839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16917104 + ... + 16917185.

It is an arithmetic number, because the mean of its divisors is an integer number (355260045).

Almost surely, 2^1387205849 is an apocalyptic number.

It is an amenable number.

1387205849 is a deficient number, since it is larger than the sum of its proper divisors (33834331).

1387205849 is an equidigital number, since it uses as much as digits as its factorization.

1387205849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33834330.

The product of its (nonzero) digits is 483840, while the sum is 47.

The square root of 1387205849 is about 37245.2124305930. The cubic root of 1387205849 is about 1115.2707283643.

The spelling of 1387205849 in words is "one billion, three hundred eighty-seven million, two hundred five thousand, eight hundred forty-nine".