1989491 has 8 divisors (see below), whose sum is σ = 2306304. Its totient is φ = 1680840.

The previous prime is 1989479. The next prime is 1989499. The reversal of 1989491 is 1949891.

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

It is a de Polignac number, because none of the positive numbers 2^k-1989491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989499) 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, 1505 + ... + 2498.

It is an arithmetic number, because the mean of its divisors is an integer number (288288).

2^1989491 is an apocalyptic number.

1989491 is a deficient number, since it is larger than the sum of its proper divisors (316813).

1989491 is an equidigital number, since it uses as much as digits as its factorization.

1989491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4081.

The product of its digits is 23328, while the sum is 41.

The square root of 1989491 is about 1410.4931761622. The cubic root of 1989491 is about 125.7710421728.

The spelling of 1989491 in words is "one million, nine hundred eighty-nine thousand, four hundred ninety-one".