1991340277 has 8 divisors (see below), whose sum is σ = 2144896160. Its totient is φ = 1842659280.

The previous prime is 1991340269. The next prime is 1991340283. The reversal of 1991340277 is 7720431991.

It is a happy number.

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 1991340277 - 2³ = 1991340269 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991340677) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1217874 + ... + 1219507.

It is an arithmetic number, because the mean of its divisors is an integer number (268112020).

Almost surely, 2^1991340277 is an apocalyptic number.

It is an amenable number.

1991340277 is a deficient number, since it is larger than the sum of its proper divisors (153555883).

1991340277 is a wasteful number, since it uses less digits than its factorization.

1991340277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2437443.

The product of its (nonzero) digits is 95256, while the sum is 43.

The square root of 1991340277 is about 44624.4358731850. The cubic root of 1991340277 is about 1258.0999911674.

The spelling of 1991340277 in words is "one billion, nine hundred ninety-one million, three hundred forty thousand, two hundred seventy-seven".