115000021 has 4 divisors (see below), whose sum is σ = 115202700. Its totient is φ = 114797344.

The previous prime is 115000009. The next prime is 115000043. The reversal of 115000021 is 120000511.

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: 120000511 = 1033 ⋅116167.

It can be written as a sum of positive squares in 2 ways, for example, as 41280625 + 73719396 = 6425^2 + 8586^2 .

It is a cyclic number.

It is not a de Polignac number, because 115000021 - 2¹³ = 114991829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 114999971 and 115000007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115000091) 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, 100486 + ... + 101623.

It is an arithmetic number, because the mean of its divisors is an integer number (28800675).

Almost surely, 2^115000021 is an apocalyptic number.

It is an amenable number.

115000021 is a deficient number, since it is larger than the sum of its proper divisors (202679).

115000021 is an equidigital number, since it uses as much as digits as its factorization.

115000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202678.

The product of its (nonzero) digits is 10, while the sum is 10.

The square root of 115000021 is about 10723.8062738936. The cubic root of 115000021 is about 486.2944427100.

Adding to 115000021 its reverse (120000511), we get a palindrome (235000532).

The spelling of 115000021 in words is "one hundred fifteen million, twenty-one", and thus it is an aban number.