6581291891 has 8 divisors (see below), whose sum is σ = 6691031568. Its totient is φ = 6471612000.

The previous prime is 6581291887. The next prime is 6581291897. The reversal of 6581291891 is 1981921856.

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

It is not a de Polignac number, because 6581291891 - 2² = 6581291887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6581291897) 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, 244061 + ... + 269681.

It is an arithmetic number, because the mean of its divisors is an integer number (836378946).

Almost surely, 2^6581291891 is an apocalyptic number.

6581291891 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

6581291891 is a deficient number, since it is larger than the sum of its proper divisors (109739677).

6581291891 is a wasteful number, since it uses less digits than its factorization.

6581291891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29893.

The product of its digits is 311040, while the sum is 50.

The square root of 6581291891 is about 81125.1618858169. The cubic root of 6581291891 is about 1874.0034423134.

The spelling of 6581291891 in words is "six billion, five hundred eighty-one million, two hundred ninety-one thousand, eight hundred ninety-one".