113216021 has 4 divisors (see below), whose sum is σ = 113264844. Its totient is φ = 113167200.

The previous prime is 113215987. The next prime is 113216027. The reversal of 113216021 is 120612311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120612311 = 61 ⋅1977251.

It can be written as a sum of positive squares in 2 ways, for example, as 39513796 + 73702225 = 6286^2 + 8585^2 .

It is a cyclic number.

It is not a de Polignac number, because 113216021 - 2⁶ = 113215957 is a prime.

It is a super-2 number, since 2×113216021² = 25635734822144882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (113216027) 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, 20750 + ... + 25631.

It is an arithmetic number, because the mean of its divisors is an integer number (28316211).

Almost surely, 2^113216021 is an apocalyptic number.

It is an amenable number.

113216021 is a deficient number, since it is larger than the sum of its proper divisors (48823).

113216021 is an equidigital number, since it uses as much as digits as its factorization.

113216021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48822.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 113216021 is about 10640.3017344434. The cubic root of 113216021 is about 483.7666911071.

Adding to 113216021 its reverse (120612311), we get a palindrome (233828332).

The spelling of 113216021 in words is "one hundred thirteen million, two hundred sixteen thousand, twenty-one".