1387786009 has 3 divisors (see below), whose sum is σ = 1387823263. Its totient is φ = 1387748756.

The previous prime is 1387785961. The next prime is 1387786027. The reversal of 1387786009 is 9006877831.

The square root of 1387786009 is 37253.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1387190025 + 595984 = 37245^2 + 772^2 .

It is not a de Polignac number, because 1387786009 - 2¹¹ = 1387783961 is a prime.

It is a super-6 number, since 6×1387786009⁶ (a number of 56 digits) contains 666666 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1387786069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 18627 + ... + 55879.

Almost surely, 2^1387786009 is an apocalyptic number.

1387786009 is the 37253-rd square number.

1387786009 is the 18627-th centered octagonal number.

It is an amenable number.

1387786009 is a deficient number, since it is larger than the sum of its proper divisors (37254).

1387786009 is an frugal number, since it uses more digits than its factorization.

1387786009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74506 (or 37253 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 49.

The cubic root of 1387786009 is about 1115.4261836117.

Multiplying 1387786009 by its sum of digits (49), we get a square (68001514441 = 260771²).

The spelling of 1387786009 in words is "one billion, three hundred eighty-seven million, seven hundred eighty-six thousand, nine".