1987209 has 12 divisors (see below), whose sum is σ = 3280576. Its totient is φ = 1135512.

The previous prime is 1987201. The next prime is 1987217. The reversal of 1987209 is 9027891.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1987201) and next prime (1987217).

It is not a de Polignac number, because 1987209 - 2³ = 1987201 is a prime.

It is a Duffinian number.

It is a Curzon number.

1987209 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1987201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15709 + ... + 15834.

2^1987209 is an apocalyptic number.

It is an amenable number.

1987209 is a deficient number, since it is larger than the sum of its proper divisors (1293367).

1987209 is a wasteful number, since it uses less digits than its factorization.

1987209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31556 (or 31553 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 1987209 is about 1409.6840071449. The cubic root of 1987209 is about 125.7229361791.

The spelling of 1987209 in words is "one million, nine hundred eighty-seven thousand, two hundred nine".