101991011 has 4 divisors (see below), whose sum is σ = 102199224. Its totient is φ = 101782800.

The previous prime is 101990983. The next prime is 101991017. The reversal of 101991011 is 110199101.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-101991011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101991017) 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, 103370 + ... + 104351.

It is an arithmetic number, because the mean of its divisors is an integer number (25549806).

Almost surely, 2^101991011 is an apocalyptic number.

101991011 is a deficient number, since it is larger than the sum of its proper divisors (208213).

101991011 is an equidigital number, since it uses as much as digits as its factorization.

101991011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208212.

The product of its (nonzero) digits is 81, while the sum is 23.

The square root of 101991011 is about 10099.0599067438. The cubic root of 101991011 is about 467.2191470849.

The spelling of 101991011 in words is "one hundred one million, nine hundred ninety-one thousand, eleven".