1661387 has 8 divisors (see below), whose sum is σ = 2044896. Its totient is φ = 1314432.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661387 is 7831661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1661387 - 2¹⁴ = 1645003 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9038 + ... + 9219.

It is an arithmetic number, because the mean of its divisors is an integer number (255612).

2^1661387 is an apocalyptic number.

1661387 is a deficient number, since it is larger than the sum of its proper divisors (383509).

1661387 is a wasteful number, since it uses less digits than its factorization.

1661387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18277.

The product of its digits is 6048, while the sum is 32.

The square root of 1661387 is about 1288.9480206742. The cubic root of 1661387 is about 118.4377829791.

It can be divided in two parts, 1661 and 387, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 1661387 in words is "one million, six hundred sixty-one thousand, three hundred eighty-seven".