102711991 has 4 divisors (see below), whose sum is σ = 103496184. Its totient is φ = 101927800.

The previous prime is 102711989. The next prime is 102712013. The reversal of 102711991 is 199117201.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 102711991 - 2¹ = 102711989 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102711911) 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, 391900 + ... + 392161.

It is an arithmetic number, because the mean of its divisors is an integer number (25874046).

Almost surely, 2^102711991 is an apocalyptic number.

102711991 is a deficient number, since it is larger than the sum of its proper divisors (784193).

102711991 is an equidigital number, since it uses as much as digits as its factorization.

102711991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784192.

The product of its (nonzero) digits is 1134, while the sum is 31.

The square root of 102711991 is about 10134.6924472329. The cubic root of 102711991 is about 468.3174955560.

The spelling of 102711991 in words is "one hundred two million, seven hundred eleven thousand, nine hundred ninety-one".