1991402767 has 8 divisors (see below), whose sum is σ = 2112052320. Its totient is φ = 1873592160.

The previous prime is 1991402747. The next prime is 1991402771. The reversal of 1991402767 is 7672041991.

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

It is a cyclic number.

It is not a de Polignac number, because 1991402767 - 2⁷ = 1991402639 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 (1991402747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 708292 + ... + 711097.

It is an arithmetic number, because the mean of its divisors is an integer number (264006540).

Almost surely, 2^1991402767 is an apocalyptic number.

1991402767 is a deficient number, since it is larger than the sum of its proper divisors (120649553).

1991402767 is a wasteful number, since it uses less digits than its factorization.

1991402767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1419473.

The product of its (nonzero) digits is 190512, while the sum is 46.

The square root of 1991402767 is about 44625.1360446106. The cubic root of 1991402767 is about 1258.1131511226.

The spelling of 1991402767 in words is "one billion, nine hundred ninety-one million, four hundred two thousand, seven hundred sixty-seven".