1991006701 has 4 divisors (see below), whose sum is σ = 2001113532. Its totient is φ = 1980899872.

The previous prime is 1991006659. The next prime is 1991006711. The reversal of 1991006701 is 1076001991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1435273225 + 555733476 = 37885^2 + 23574^2 .

It is a cyclic number.

It is not a de Polignac number, because 1991006701 - 2¹⁹ = 1990482413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991006711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5053120 + ... + 5053513.

It is an arithmetic number, because the mean of its divisors is an integer number (500278383).

Almost surely, 2^1991006701 is an apocalyptic number.

It is an amenable number.

1991006701 is a deficient number, since it is larger than the sum of its proper divisors (10106831).

1991006701 is a wasteful number, since it uses less digits than its factorization.

1991006701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10106830.

The product of its (nonzero) digits is 3402, while the sum is 34.

The square root of 1991006701 is about 44620.6981231805. The cubic root of 1991006701 is about 1258.0297377468.

The spelling of 1991006701 in words is "one billion, nine hundred ninety-one million, six thousand, seven hundred one".