1387561 has 4 divisors (see below), whose sum is σ = 1585792. Its totient is φ = 1189332.

The previous prime is 1387531. The next prime is 1387571. The reversal of 1387561 is 1657831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1387561 - 2⁷ = 1387433 is a prime.

It is a Duffinian number.

1387561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1387501) 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, 99105 + ... + 99118.

It is an arithmetic number, because the mean of its divisors is an integer number (396448).

2^1387561 is an apocalyptic number.

It is an amenable number.

1387561 is a deficient number, since it is larger than the sum of its proper divisors (198231).

1387561 is an equidigital number, since it uses as much as digits as its factorization.

1387561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198230.

The product of its digits is 5040, while the sum is 31.

The square root of 1387561 is about 1177.9477917123. The cubic root of 1387561 is about 111.5365897061.

The spelling of 1387561 in words is "one million, three hundred eighty-seven thousand, five hundred sixty-one".