115821953 has 6 divisors (see below), whose sum is σ = 125416854. Its totient is φ = 106912416.

The previous prime is 115821869. The next prime is 115821991. The reversal of 115821953 is 359128511.

115821953 = 202² + 203² + ... + 708².

It can be written as a sum of positive squares in 3 ways, for example, as 753424 + 115068529 = 868^2 + 10727^2 .

It is a de Polignac number, because none of the positive numbers 2^k-115821953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115824953) 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, 342500 + ... + 342837.

It is an arithmetic number, because the mean of its divisors is an integer number (20902809).

Almost surely, 2^115821953 is an apocalyptic number.

115821953 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

115821953 is a deficient number, since it is larger than the sum of its proper divisors (9594901).

115821953 is an equidigital number, since it uses as much as digits as its factorization.

115821953 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685363 (or 685350 counting only the distinct ones).

The product of its digits is 10800, while the sum is 35.

The square root of 115821953 is about 10762.0608156617. The cubic root of 115821953 is about 487.4502467743.

The spelling of 115821953 in words is "one hundred fifteen million, eight hundred twenty-one thousand, nine hundred fifty-three".