1099987 has 4 divisors (see below), whose sum is σ = 1257136. Its totient is φ = 942840.

The previous prime is 1099961. The next prime is 1099997. The reversal of 1099987 is 7899901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7899901 = 47 ⋅168083.

It is a cyclic number.

It is not a de Polignac number, because 1099987 - 2⁷ = 1099859 is a prime.

It is a Duffinian number.

1099987 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1099927) 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, 78564 + ... + 78577.

It is an arithmetic number, because the mean of its divisors is an integer number (314284).

2^1099987 is an apocalyptic number.

1099987 is a deficient number, since it is larger than the sum of its proper divisors (157149).

1099987 is an equidigital number, since it uses as much as digits as its factorization.

1099987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157148.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 1099987 is about 1048.8026506450. The cubic root of 1099987 is about 103.2276048882.

The spelling of 1099987 in words is "one million, ninety-nine thousand, nine hundred eighty-seven".