101991012 has 96 divisors (see below), whose sum is σ = 261381120. Its totient is φ = 30844800.

The previous prime is 101990983. The next prime is 101991017. The reversal of 101991012 is 210199101.

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 31 ways as a sum of consecutive naturals, for example, 990153 + ... + 990255.

It is an arithmetic number, because the mean of its divisors is an integer number (2722720).

Almost surely, 2^101991012 is an apocalyptic number.

101991012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 101991012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130690560).

101991012 is an abundant number, since it is smaller than the sum of its proper divisors (159390108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

101991012 is a wasteful number, since it uses less digits than its factorization.

101991012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 24.

The square root of 101991012 is about 10099.0599562534. The cubic root of 101991012 is about 467.2191486119.

It can be divided in two parts, 10199 and 1012, that added together give a palindrome (11211).

The spelling of 101991012 in words is "one hundred one million, nine hundred ninety-one thousand, twelve".