1991026734 has 16 divisors (see below), whose sum is σ = 3983493072. Its totient is φ = 663435648.

The previous prime is 1991026669. The next prime is 1991026769. The reversal of 1991026734 is 4376201991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41569 + ... + 75564.

It is an arithmetic number, because the mean of its divisors is an integer number (248968317).

Almost surely, 2^1991026734 is an apocalyptic number.

1991026734 is an abundant number, since it is smaller than the sum of its proper divisors (1992466338).

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

1991026734 is a wasteful number, since it uses less digits than its factorization.

1991026734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119971.

The product of its (nonzero) digits is 81648, while the sum is 42.

The square root of 1991026734 is about 44620.9226036397. The cubic root of 1991026734 is about 1258.0339570571.

The spelling of 1991026734 in words is "one billion, nine hundred ninety-one million, twenty-six thousand, seven hundred thirty-four".