1991526 has 8 divisors (see below), whose sum is σ = 3983064. Its totient is φ = 663840.

The previous prime is 1991519. The next prime is 1991527. The reversal of 1991526 is 6251991.

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

1991526 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991527) 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, 165955 + ... + 165966.

It is an arithmetic number, because the mean of its divisors is an integer number (497883).

2^1991526 is an apocalyptic number.

1991526 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1991526 is a wasteful number, since it uses less digits than its factorization.

1991526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331926.

The product of its digits is 4860, while the sum is 33.

The square root of 1991526 is about 1411.2143706751. The cubic root of 1991526 is about 125.8139102320.

The spelling of 1991526 in words is "one million, nine hundred ninety-one thousand, five hundred twenty-six".