6991143261 has 32 divisors (see below), whose sum is σ = 9656845440. Its totient is φ = 4496083200.

The previous prime is 6991143253. The next prime is 6991143277. The reversal of 6991143261 is 1623411996.

It is not a de Polignac number, because 6991143261 - 2³ = 6991143253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991143251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5919091 + ... + 5920271.

It is an arithmetic number, because the mean of its divisors is an integer number (301776420).

Almost surely, 2^6991143261 is an apocalyptic number.

It is an amenable number.

6991143261 is a deficient number, since it is larger than the sum of its proper divisors (2665702179).

6991143261 is a wasteful number, since it uses less digits than its factorization.

6991143261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757.

The product of its digits is 69984, while the sum is 42.

The square root of 6991143261 is about 83613.0567614891. The cubic root of 6991143261 is about 1912.1240645506.

The spelling of 6991143261 in words is "six billion, nine hundred ninety-one million, one hundred forty-three thousand, two hundred sixty-one".