115440021 has 6 divisors (see below), whose sum is σ = 166746710. Its totient is φ = 76960008.

The previous prime is 115439971. The next prime is 115440113. The reversal of 115440021 is 120044511.

It can be written as a sum of positive squares in only one way, i.e., 64160100 + 51279921 = 8010^2 + 7161^2 .

It is not a de Polignac number, because 115440021 - 2⁶ = 115439957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 115439976 and 115440003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115440821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6413326 + ... + 6413343.

Almost surely, 2^115440021 is an apocalyptic number.

It is an amenable number.

115440021 is a deficient number, since it is larger than the sum of its proper divisors (51306689).

115440021 is a wasteful number, since it uses less digits than its factorization.

115440021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12826675 (or 12826672 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 115440021 is about 10744.3017921129. The cubic root of 115440021 is about 486.9138549004.

Adding to 115440021 its reverse (120044511), we get a palindrome (235484532).

The spelling of 115440021 in words is "one hundred fifteen million, four hundred forty thousand, twenty-one".