4991561839 has 8 divisors (see below), whose sum is σ = 5731937280. Its totient is φ = 4298952600.

The previous prime is 4991561831. The next prime is 4991561881. The reversal of 4991561839 is 9381651994.

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 4991561839 - 2³ = 4991561831 is a prime.

It is a super-2 number, since 2×4991561839² = 49831379185122123842, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 4991561839.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4991561831) 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, 11941327 + ... + 11941744.

It is an arithmetic number, because the mean of its divisors is an integer number (716492160).

Almost surely, 2^4991561839 is an apocalyptic number.

4991561839 is a deficient number, since it is larger than the sum of its proper divisors (740375441).

4991561839 is a wasteful number, since it uses less digits than its factorization.

4991561839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23883101.

The product of its digits is 2099520, while the sum is 55.

The square root of 4991561839 is about 70650.9861148449. The cubic root of 4991561839 is about 1709.0134682140.

The spelling of 4991561839 in words is "four billion, nine hundred ninety-one million, five hundred sixty-one thousand, eight hundred thirty-nine".