115519721 has 2 divisors, whose sum is σ = 115519722. Its totient is φ = 115519720.

The previous prime is 115519711. The next prime is 115519727. The reversal of 115519721 is 127915511.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115326121 + 193600 = 10739^2 + 440^2 .

It is an emirp because it is prime and its reverse (127915511) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115519721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (115519727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57759860 + 57759861.

It is an arithmetic number, because the mean of its divisors is an integer number (57759861).

Almost surely, 2^115519721 is an apocalyptic number.

It is an amenable number.

115519721 is a deficient number, since it is larger than the sum of its proper divisors (1).

115519721 is an equidigital number, since it uses as much as digits as its factorization.

115519721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3150, while the sum is 32.

The square root of 115519721 is about 10748.0100948966. The cubic root of 115519721 is about 487.0258845255.

The spelling of 115519721 in words is "one hundred fifteen million, five hundred nineteen thousand, seven hundred twenty-one".