118721521 has 4 divisors (see below), whose sum is σ = 120493552. Its totient is φ = 116949492.

The previous prime is 118721509. The next prime is 118721543. The reversal of 118721521 is 125127811.

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.

It is a cyclic number.

It is not a de Polignac number, because 118721521 - 2¹⁵ = 118688753 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 118721521.

It is not an unprimeable number, because it can be changed into a prime (118721021) 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, 885915 + ... + 886048.

It is an arithmetic number, because the mean of its divisors is an integer number (30123388).

Almost surely, 2^118721521 is an apocalyptic number.

It is an amenable number.

118721521 is a deficient number, since it is larger than the sum of its proper divisors (1772031).

118721521 is an equidigital number, since it uses as much as digits as its factorization.

118721521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1772030.

The product of its digits is 1120, while the sum is 28.

The square root of 118721521 is about 10895.9405743607. The cubic root of 118721521 is about 491.4844901754.

The spelling of 118721521 in words is "one hundred eighteen million, seven hundred twenty-one thousand, five hundred twenty-one".