1991648594 has 32 divisors (see below), whose sum is σ = 3292289280. Its totient is φ = 897869952.

The previous prime is 1991648531. The next prime is 1991648653. The reversal of 1991648594 is 4958461991.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 755102 + ... + 757734.

It is an arithmetic number, because the mean of its divisors is an integer number (102884040).

Almost surely, 2^1991648594 is an apocalyptic number.

1991648594 is a deficient number, since it is larger than the sum of its proper divisors (1300640686).

1991648594 is a wasteful number, since it uses less digits than its factorization.

1991648594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3314.

The product of its digits is 2799360, while the sum is 56.

The square root of 1991648594 is about 44627.8903153622. The cubic root of 1991648594 is about 1258.1649178908.

The spelling of 1991648594 in words is "one billion, nine hundred ninety-one million, six hundred forty-eight thousand, five hundred ninety-four".