113721 has 4 divisors (see below), whose sum is σ = 151632. Its totient is φ = 75812.

The previous prime is 113719. The next prime is 113723. The reversal of 113721 is 127311.

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: 127311 = 3 ⋅42437.

It is an interprime number because it is at equal distance from previous prime (113719) and next prime (113723).

It is a cyclic number.

It is not a de Polignac number, because 113721 - 2¹ = 113719 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 113721.

It is not an unprimeable number, because it can be changed into a prime (113723) 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, 18951 + ... + 18956.

It is an arithmetic number, because the mean of its divisors is an integer number (37908).

2¹¹³⁷²¹ is an apocalyptic number.

It is an amenable number.

113721 is a deficient number, since it is larger than the sum of its proper divisors (37911).

113721 is an equidigital number, since it uses as much as digits as its factorization.

113721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37910.

The product of its digits is 42, while the sum is 15.

The square root of 113721 is about 337.2254438799. The cubic root of 113721 is about 48.4484874831.

The spelling of 113721 in words is "one hundred thirteen thousand, seven hundred twenty-one".