115402991 has 4 divisors (see below), whose sum is σ = 125894184. Its totient is φ = 104911800.

The previous prime is 115402981. The next prime is 115403027. The reversal of 115402991 is 199204511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199204511 = 11 ⋅18109501.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115402991 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 (115402901) 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, 5245580 + ... + 5245601.

It is an arithmetic number, because the mean of its divisors is an integer number (31473546).

Almost surely, 2^115402991 is an apocalyptic number.

115402991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

115402991 is a deficient number, since it is larger than the sum of its proper divisors (10491193).

115402991 is a wasteful number, since it uses less digits than its factorization.

115402991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10491192.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 115402991 is about 10742.5784148872. The cubic root of 115402991 is about 486.8617864521.

The spelling of 115402991 in words is "one hundred fifteen million, four hundred two thousand, nine hundred ninety-one".