113621521 has 4 divisors (see below), whose sum is σ = 122361652. Its totient is φ = 104881392.

The previous prime is 113621509. The next prime is 113621531. The reversal of 113621521 is 125126311.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125126311 = 61 ⋅2051251.

It can be written as a sum of positive squares in 2 ways, for example, as 11833600 + 101787921 = 3440^2 + 10089^2 .

It is a cyclic number.

It is not a de Polignac number, because 113621521 - 2⁷ = 113621393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 113621492 and 113621501.

It is not an unprimeable number, because it can be changed into a prime (113621531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4370046 + ... + 4370071.

It is an arithmetic number, because the mean of its divisors is an integer number (30590413).

Almost surely, 2^113621521 is an apocalyptic number.

It is an amenable number.

113621521 is a deficient number, since it is larger than the sum of its proper divisors (8740131).

113621521 is an equidigital number, since it uses as much as digits as its factorization.

113621521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8740130.

The product of its digits is 360, while the sum is 22.

The square root of 113621521 is about 10659.3396136909. The cubic root of 113621521 is about 484.3435636955.

Adding to 113621521 its reverse (125126311), we get a palindrome (238747832).

The spelling of 113621521 in words is "one hundred thirteen million, six hundred twenty-one thousand, five hundred twenty-one".