10115991 has 6 divisors (see below), whose sum is σ = 14612000. Its totient is φ = 6743988.

The previous prime is 10115953. The next prime is 10115993. The reversal of 10115991 is 19951101.

It is not a de Polignac number, because 10115991 - 2⁶ = 10115927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10115993) 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, 561991 + ... + 562008.

Almost surely, 2^10115991 is an apocalyptic number.

10115991 is a deficient number, since it is larger than the sum of its proper divisors (4496009).

10115991 is a wasteful number, since it uses less digits than its factorization.

10115991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1124005 (or 1124002 counting only the distinct ones).

The product of its (nonzero) digits is 405, while the sum is 27.

The square root of 10115991 is about 3180.5645725248. The cubic root of 10115991 is about 216.2732524252.

The spelling of 10115991 in words is "ten million, one hundred fifteen thousand, nine hundred ninety-one".