118987721 has 4 divisors (see below), whose sum is σ = 120421392. Its totient is φ = 117554052.

The previous prime is 118987663. The next prime is 118987723. The reversal of 118987721 is 127789811.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127789811 = 59 ⋅2165929.

It is a cyclic number.

It is not a de Polignac number, because 118987721 - 2⁶ = 118987657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (118987723) 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, 716711 + ... + 716876.

It is an arithmetic number, because the mean of its divisors is an integer number (30105348).

Almost surely, 2^118987721 is an apocalyptic number.

It is an amenable number.

118987721 is a deficient number, since it is larger than the sum of its proper divisors (1433671).

118987721 is an equidigital number, since it uses as much as digits as its factorization.

118987721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433670.

The product of its digits is 56448, while the sum is 44.

The square root of 118987721 is about 10908.1492930744. The cubic root of 118987721 is about 491.8515550685.

The spelling of 118987721 in words is "one hundred eighteen million, nine hundred eighty-seven thousand, seven hundred twenty-one".