101991042 has 16 divisors (see below), whose sum is σ = 226646880. Its totient is φ = 33996996.

The previous prime is 101991017. The next prime is 101991047. The reversal of 101991042 is 240199101.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 101990997 and 101991015.

It is not an unprimeable number, because it can be changed into a prime (101991047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 944308 + ... + 944415.

It is an arithmetic number, because the mean of its divisors is an integer number (14165430).

Almost surely, 2^101991042 is an apocalyptic number.

101991042 is an abundant number, since it is smaller than the sum of its proper divisors (124655838).

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

101991042 is a wasteful number, since it uses less digits than its factorization.

101991042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1888734 (or 1888728 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 101991042 is about 10099.0614415400. The cubic root of 101991042 is about 467.2191944218.

The spelling of 101991042 in words is "one hundred one million, nine hundred ninety-one thousand, forty-two".