6991771 has 8 divisors (see below), whose sum is σ = 7394688. Its totient is φ = 6600000.

The previous prime is 6991741. The next prime is 6991783. The reversal of 6991771 is 1771996.

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 6991771 - 2¹³ = 6983579 is a prime.

It is a Duffinian number.

6991771 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6991711) 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, 1480 + ... + 4021.

It is an arithmetic number, because the mean of its divisors is an integer number (924336).

Almost surely, 2^6991771 is an apocalyptic number.

6991771 is a deficient number, since it is larger than the sum of its proper divisors (402917).

6991771 is a wasteful number, since it uses less digits than its factorization.

6991771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5573.

The product of its digits is 23814, while the sum is 40.

The square root of 6991771 is about 2644.1957189285. The cubic root of 6991771 is about 191.2181293098.

The spelling of 6991771 in words is "six million, nine hundred ninety-one thousand, seven hundred seventy-one".