1187909983 has 4 divisors (see below), whose sum is σ = 1279287688. Its totient is φ = 1096532280.

The previous prime is 1187909981. The next prime is 1187909993. The reversal of 1187909983 is 3899097811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3899097811 = 7 ⋅557013973.

It is a cyclic number.

It is not a de Polignac number, because 1187909983 - 2¹ = 1187909981 is a prime.

It is a super-2 number, since 2×1187909983² = 2822260255422120578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187909981) 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, 45688833 + ... + 45688858.

It is an arithmetic number, because the mean of its divisors is an integer number (319821922).

Almost surely, 2^1187909983 is an apocalyptic number.

1187909983 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1187909983 is a deficient number, since it is larger than the sum of its proper divisors (91377705).

1187909983 is an equidigital number, since it uses as much as digits as its factorization.

1187909983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91377704.

The product of its (nonzero) digits is 979776, while the sum is 55.

The square root of 1187909983 is about 34466.0700254613. The cubic root of 1187909983 is about 1059.0777498072.

The spelling of 1187909983 in words is "one billion, one hundred eighty-seven million, nine hundred nine thousand, nine hundred eighty-three".