1991242 has 8 divisors (see below), whose sum is σ = 3258432. Its totient is φ = 905100.

The previous prime is 1991239. The next prime is 1991243. The reversal of 1991242 is 2421991.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1991242.

It is not an unprimeable number, because it can be changed into a prime (1991243) 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, 45234 + ... + 45277.

It is an arithmetic number, because the mean of its divisors is an integer number (407304).

2^1991242 is an apocalyptic number.

1991242 is a deficient number, since it is larger than the sum of its proper divisors (1267190).

1991242 is a wasteful number, since it uses less digits than its factorization.

1991242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90524.

The product of its digits is 1296, while the sum is 28.

The square root of 1991242 is about 1411.1137445295. The cubic root of 1991242 is about 125.8079294164.

It can be divided in two parts, 199 and 1242, that added together give a palindrome (1441).

The spelling of 1991242 in words is "one million, nine hundred ninety-one thousand, two hundred forty-two".