1187999 has 2 divisors, whose sum is σ = 1188000. Its totient is φ = 1187998.

The previous prime is 1187993. The next prime is 1188001. The reversal of 1187999 is 9997811.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1187999 - 2²⁰ = 139423 is a prime.

It is a super-2 number, since 2×1187999² = 2822683248002, which contains 22 as substring.

Together with 1188001, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1187993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 593999 + 594000.

It is an arithmetic number, because the mean of its divisors is an integer number (594000).

2^1187999 is an apocalyptic number.

1187999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1187999 is an equidigital number, since it uses as much as digits as its factorization.

1187999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 44.

The square root of 1187999 is about 1089.9536687401. The cubic root of 1187999 is about 105.9104203430.

The spelling of 1187999 in words is "one million, one hundred eighty-seven thousand, nine hundred ninety-nine".